Next Article in Journal
The Corrosion Resistance of Reinforced Lightweight Aggregate Concrete in Strong Brine Environments
Next Article in Special Issue
High Ampacity On-Chip Wires Implemented by Aligned Carbon Nanotube-Cu Composite
Previous Article in Journal
Electrostatic Analysis of Bioactivity of Ti-6Al-4V Hydrophilic Surface with Laser Textured Micro-Square Convexes
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Materials
Volume 15
Issue 22
10.3390/ma15227941
materials-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

The Effects of Pt-Doped TiO2 Nanoparticles and Thickness of Semiconducting Layers at Photoanode in the Improved Performance of Dye-Sensitized Solar Cells

by
M. Mujahid
1,* and
Omar A. Al-Hartomy
2
1
Physics Section, SHSSSB, Aligarh Muslim University, Aligarh 202002, India
2
Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
*
Author to whom correspondence should be addressed.
Materials 2022, 15(22), 7941; https://doi.org/10.3390/ma15227941
Submission received: 9 August 2022 / Revised: 26 October 2022 / Accepted: 31 October 2022 / Published: 10 November 2022
(This article belongs to the Special Issue Carbon Nanotubes: Preparation and Functional Applications)
Browse Figures
Review Reports Versions Notes

Abstract

:
This work synthesized Pt-doped dye-sensitized solar cells (DSSC) with different molar ratios and thicknesses. The materials were revealed fully through X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). The photovoltaic properties of the sample were studied by UV-visible spectroscopy, electrochemical impedance spectroscopy (EIS), and IPEC (incident photon-to-current conversion efficiency) techniques. EIS analysis established the decrease in series resistance at the electrolyte interface. It could be one of the reasons for the increase in electron transfer rate and decrease in the recombination process at the interface. Statistical data obtained from optical and electrical investigations revealed that the electrical power-output efficiency of DSSC was 14.25%. It was found that a high ratio of Pt doping and thinner thickness can promote cell performance, owing to the reduction of series resistance, lower bandgap, and high dye adsorption. Doping TiO2 with Pt reduced its energy bandgap and introduces intermediate energy levels inside TiO2 to facilitate the transition of electrons at low excitation energies. The absorbance of the samples 0.15 M Pt and 0.25 M Pt showed improvement in the wavelength ranging from 200 to 800 nm by Pt doping.

1. Introduction

The dye-sensitized solar cell (DSSC) is an inexpensive and versatile cell that is based on photovoltaic technology. It contains a semiconductor between a photosensitized anode, dye, liquid electrolyte, separator, and counter electrode. It converts solar light into useful energy. This photovoltaic cell, also called the Grätzel cell, was devised by Brian O’Regan and Michael Grätzel [1].
Titanium dioxide (TiO2) is also known as a metal oxide nanoparticle (MO-NPS) [2]. It is chemically stable and non-toxic. [3]. Compared with other MO-NPS such as, for example, Al2O3, CuO, CO3O4, Cr2O3, Fe3O4, La2O3, Mn2O3, NiO, ZnO, and ZrO2 with energy bandgaps of 8.30 eV, 1.34 eV, 2.43 eV, 3.08 eV, 1.85 eV, 5.77 eV, 2.99 eV, 3.66 eV, 3.31 eV, and 5.04 eV respectively, the energy bandgap of TiO2 is 3.2 eV [4,5,6]. TiO2 shows electron diffusivity, large binding energy, and bulk mobility [7,8]. TiO2 is used in many electronic devices, such as variable resistors [9,10], piezoelectric devices, and transducers [11,12]. There are several methods to synthesize TiO2, such as co-precipitation, ball-milling, sol–gel, and the hydrothermal method [13,14].
TiO2 is UV-active, and doping TiO2 with Pt supports its photocatalytic behavior toward visible light. Pt is a valuable noble metal and a perovskite booster [15]. Doping TiO2 with Pt reduces its energy bandgap and introduces intermediate energy levels inside TiO2 to facilitate the transition of electrons at low excitation energies.
This publication’s novelty is to improve solar cell efficiency; with this objective, we tailored and processed the synthesis of Pt-doped DSSC with different molar ratios and thicknesses. We found that a high molar ratio of Pt doping and thinner thickness can promote cell performance. This work will be advantageous for studying indoor and outdoor panel displays, glass tiles, and many nanostructure-based devices [16,17,18].
Many researchers have investigated the effects of doping and the thickness of photoandes on synthesizing DSSC. In 2004, Meyer et al. used bis-tetra-butylammonium (N719 dye) and calculated the output efficiency of the cell as 11.2% [19]. In 2014, Korake et al. published research using a naphthyridine complex compound and found a maximum power conversion efficiency of 7% [20]. In 1998, Lieber et al. determined the effect of the TiO2 nanospindle photoanodes and achieved an efficiency of 8.30% [21]. In 2020, Chih-Hung et al. used triethylamine to form Cu2 Zn Sn S4 nanoparticles to fabricate solar cells [22]. In 2022, Chen et al. used nano-ferrite zinc-rich materials to fabricate DSSC [23]. Thus, to improve cell performance, the new materials were synthesized and applied to the photo-anode of the DSSC. To date, the enhancement in cell efficiency was recorded to be 33.8% using FeT-based samples [24].
Indeed, some electrical characterization is necessary to flag and fix the effortless charge transport and charge separation characteristics for passive and possible maintenance of the output power efficiency of the cell.

2. Experimental Techniques

2.1. Chemicals and Reagents

3-Chloroperbenzoic acid (3-CPBA), titanium IV oxysulfate hydrate, platinum nitrate, ammonium hexachloroplatinate, and bis-tetra-butylammonium (N719) dye) were procured from Sigma-Aldrich Company, St. Louis, MO, USA. Surfactant Triton X-100, benzene, 2-propanol, ethyl alcohol, acetic acid, and sulphuric acid were procured from Merck Company, St. Louis, NJ, USA. All the reagents used were of analytical grade.

2.2. Hydrothermal Processing

The hydrothermal process is a cheaper synthesis process to obtain nanoparticles of uniform shapes and sizes. Oxides, sulfide, carbonate, and tungsten nanoparticles can be easily synthesized using this process.
In the hydrothermal process, chemical precursors were dissolved in water in an autoclave containing temperature and pressure control gauges. To start this process, a mixture of 9 g of titanium IV oxysulfate hydrate powder was stirred inside the autoclave at 180 °C for 24 h with 5 g of 3-CPBA in 200 mL of benzene followed by centrifugation for one hour. The solid material collected after centrifugation was washed 3–4 times with deionized water and ethyl alcohol. Finally, the collected materials were dried at 90 °C for 7 h.
A total of 3 g of surfactant Triton X-100 prepared in 500 mL of deionized water was regularly stirred for 10 h in an oven containing 2 g of titanium IV oxysulfate hydrate prepared in 50 mL of isopropyl alcohol. Following this, both solutions were mixed. Then, 50 mL of concentrated sulfuric acid was added dropwise into the solution under continuous magnetic stirring at 50 °C for 10 h. The synthesized materials underwent hydrothermal treatment at 180 °C for 24 h. The mixture was finally cooled at room temperature, and the collected solid materials were filtered and washed with distilled water and ethanol, followed by air-drying. The sample was then calcinated at 400 °C for 16 h in a nitrogen atmosphere. For doping of TiO2 with Pt, different molarity concentrations of platinum nitrate (0.15 M Pt, 0.25 M Pt, 0.35 M Pt, and 0.45 M Pt) were added dropwise into the surfactant solution.

2.3. Layering Procedure on the Photo Anodes and Their Control

The vital role of synthesizing the cell was to prepare the paste. To start with, the synthesized material was mixed with 0.035 M dilute acetic acid and 2–3 mL of Triton X 100 to prepare a paste. The film thickness was controlled by the number of tapes used for the doctor blade method [25]. The prepared paste was coated on the FTO glass. The glass plate was warmed at 450 °C with the help of electric hot plates for 40 min and allowed to cool at room temperature. Three different thicknesses of semiconducting layers, namely, 12 μm, 16 μm, and 20 μm, were prepared following this method by controlling time, pasted material, and temperature. The surface profiler was used to measure the film thickness.
Each FTO glass plate prepared by the above method was dipped in a beaker containing 0.5 mM ethanol solution and N719 dye for 8 h. To boost electron recombination and charge transfer, the working electrode of the cell was coated with platinum. The electrolyte with iodine content was introduced into the cell. Hot melt foil seal cathodic and anodic plates were used to protect the cell from short-circuiting, leakage, and solvent evaporation.

2.4. Electrochemical Impedance Spectroscopy (EIS)-Nyquist Curve

The EIS–Nyquist curve was plotted with the help of software. Accordingly, precise values of fitted resistance, capacitance, and constant phase element were obtained.

2.5. Characterization Equipment

The prepared samples were characterized by an XRD-having wavelength λ = 0.15418 nm. A UV–VIS spectrophotometer, Jasco, OR, USA, modal number V-770, was used to analyze the absorption spectrum. TEM carried out shapes, sizes, and particle size distribution under different magnifications. A semi-automated Keithley (British Columbian Company) meter modal 2611A was used to obtain the current-voltage characteristics curve. The IPEC spectrum was measured by a multimeter, model number PEC S-20. EIS measurement was carried out using an impedance analyzer in the frequency range of 20 Hz to 1 MHz. The stylus profiler measured the sample thickness.
Figure 1 depicts the schematic representation of the cell containing Pt-doped TiO2 coated on the FTO conductive glass plate sensitized with dye. A separator separated the anode and cathode. The liquid electrolyte of iodide/tri-iodide redox couple was injected through the hole drilled towards the counter electrode. The cathode also consisted of an FTO conductive glass plate with a deposited platinum layer. When light was incident on the photoanode of the cell, electrons moved from the valance band to the conduction band. Hence, a voltage was set up across the junction.

3. Analysis of Results

3.1. Analysis of the XRD Result

Figure 2 represents an XRD graph of Pt-doped and undoped TiO2 samples with different molar ratios. Comparing the XRD graph with JCPDS card number 21-1272, the phase of TiO2 was indexed as the anatase phase [25]. The XRD graph consisted of four diffraction peaks at 25.2, 38.9, 48.0, and 53.0 at angle 2theta (degrees). These peaks corresponded to diffraction planes of (101), (004), (200), and (105), respectively. No characteristic peaks of other defects were observed. These results indicated that the products had crystallinity and purity.
The diffraction peaks of Pt-doped TiO2 NPs were in good agreement with those of the anatase phase of the TiO2 and were almost identical to those of undoped TiO2, indicating that the Pt atoms were doped into the TiO2 crystal. With the increase in Pt doping concentration, the diffraction peaks remained at the same diffraction angle and the exact location; this illustrated that the anatase crystalline phase of TiO2 remained unchanged with Pt doping. The peak intensity increased with increasing doping concentrations. This was due to the expansion of the unit cell, which was due to the presence of Pt ions at the interstitial site of TiO2. Our XRD result was in good agreement with the reported result of Rosario and Pereira [26].
The full width at half maxima (FWHM) of the diffraction peak (101) was used to calculate crystallite size (dhkl). The Scherrer formula [27] was used to calculate the crystallite size of the diffraction peak (101), and its value was found to be 20 nm.
dhkl = 0.9λ/βcosƟ
where Ɵ is the diffraction angle, β is FWHM, and λ is the wavelength of light used.

3.2. UV-Visible Spectra

Figure 3 shows the UV-visible spectrum of TiO2 samples doped with the distinct molar ratio of Pt. The absorbance of the samples 0.15 M Pt and 0.25 M Pt showed improvement in the wavelength ranging from 200 to 800 nm by Pt doping. Although there was no improvement in absorbance in the samples doped with 0.35 M Pt and 0.45 M Pt, we may speculate some organic molecules, such as surfactants, may have modified the pattern. However, other samples doped with 0.15 M Pt and 0.25 M Pt showed clear improvement in absorbance compared to undoped samples.
It is also clear from Figure 3 that after doping, the absorption edge shifted from 360 nm to 460 nm. This shift was ascribed to the reduction of the bandgap. This observation was the same as the reported value of Chunqiao et al. in the case of doping of TiO2 by La and Eu [27]. The bandgap energies (Eg) of synthesized material were found using the Tauc formula given by Equation (2):
(αhν)2 = hν − Eg
When the value of (αhν)2 was plotted on the y-axis, and photon energy E (eV) was plotted on the x-axis, then the pattern of this graph was as shown in Figure 4.
If we compare Equation (2) with linear equation y = mx − c, by putting y = 0, Equation (2) can be reduced to
Eg = hν
When the linear region of the curve drawn in Figure 4 is additionally plotted, their intersection on the x-axis will provide bandgap energy. The calculated Eg values for undoped and doped samples using the calculation shown Figure 4 were found to be 3.2 eV (undoped TiO2), 3.02 eV (TiO2 doped with 0.15 M Pt), 2.9 eV (TiO2 doped with 0.25 M Pt), 2.84 eV (TiO2 doped with 0.35 M Pt), and 2.75 eV (TiO2 doped with 0.45 M Pt). The energy bandgap values of Pt-doped samples were observed to be diminutive in energy than undoped samples. Due to this reduction in energy bands, Pt-doped TiO2 material showed an increase in photovoltaic action under sunlight irradiation [28]. The bandgap reduction was due to the formation of substitutional defects by incorporating Pt ions into the TiO2 crystal [29]. Defects, in general, are defined as those in which there are irregularities in the arrangements of constituent particles.

3.3. TEM Analysis

Figure 5 shows the TEM image of one of the samples doped with 0.25 M of Pt onto TiO2 composite material. Figure 5 also indicates that the mean dimension of synthesized TiO2 nanoparticles was 20 nm. Thus, results obtained from TEM appear to be compatible with the results obtained using the Scherrer formula. These two methods provide good information about synthesized NP size and morphology. We also found dark-colored particles overlapping TiO2 particles. They seemed agglomerated because of the complexing agent used during the sample preparation.

3.4. EDS Spectra

Figure 6 represents the energy dispersive spectroscopy (EDS) spectra of the synthesized material. EDS provides information about qualitative and semi-quantitative data analysis [30]. The spectra showed three different peaks of Ti, O, and Pt. The peak intensity of Pt was very small. This confirmed the doping of Pt on TiO2. Additionally, EDS spectra quantitatively confirmed the weight and atomic weight (%) of Ti, O, and Pt.

3.5. Electrical Properties

3.5.1. Performance of DSSC

The photovoltaic performance was studied using a solar photovoltaic radiator AM 1.5 G of intensity 100 mW/cm2. The characteristic curve for undoped and doped material is plotted in Figure 7. Equations (3) and (4) were used to calculate the electrical properties of DSSC and summarized in Table 1.
The equation estimated the efficiency of the DSSC.
η% = FF × Jsc × Voc/Pi
The fill factor (FF) was calculated by the following equation:
FF = Jmax × Vmax/Jsc × Voc.
where Jmax and Vmax represent maximum current density and maximum output potential. The Keithley meter was used to obtain a current–voltage characteristic curve. It was clear from the current–voltage characteristic curve that the short circuit current increased with doping concentration. Thus, with increasing doping concentration, the current density, open circuit voltage, fill factor, and efficiency of the cell increased.

3.5.2. Electrochemical Impedance Spectroscopy

Electrochemical impedance spectroscopy (EIS) is used to analyze Lissajous figures. Electrochemical impedance is the electrical parameters of the circuit. Impedance is measured by applying a small signal. EIS can be used to study the charge transfer and diffusion process. The impedance of the cell is described as the sum of real and imaginary parts given by
Z*(ω) = Z′(ω) + jZ′′(ω)
If the real part is plotted on the x-axis and the imaginary negative part on the y-axis, we obtain a plot called the Nyquist plot. Figure 8 shows the Nyquist plot of our synthesized solar cell. This plot informs us about charge transfer from the solution to the electrode surface. The intercept of the semi-circles on the x-axis near the origin represents the cell’s series resistance (Rs). This plot was conducted at high frequency. Accordingly, the intercept of the consecutive plots near the origin were 4 Ω, 5 Ω, 6 Ω, 7 Ω, and 11 Ω corresponding to samples doped with 0.45 M Pt, 0.35 M Pt, 0.25 M Pt, and 0.15 M Pt, as well as the undoped sample, respectively. Thus, with increasing doping concentration, the series resistance of the cell decreased. Our findings exactly match the results obtained by Yang et al. in the case of TiO2 nanotubes treated with TiCl4 [30,31,32]. Thus, we found a very important intrinsic material property: doping of the sample at high molar concentration favored the ability of the DSSC to transfer an electron from the solution to the electrode surface, influencing conductivity, current density, and efficiency.
We also found a straight line corresponding to 0.35 M Pt. The intersection of this line on the x-axis provided us with a resistance that not only depended on frequency but corresponded to the diffusion of redox species at the electrode–electrolyte interface. This resistance is called the Warburg resistance [33,34,35].
When each feature of the EIS was characterized by an electrical circuit using software that contains resistance, capacitance, or constant phase elements that are connected in series or parallel to form an equivalent circuit, as shown in Figure 9, then we found that the resistance R1 was in parallel with the constant phase element CPE1, which was responsible for impedance at the Pt/electrolyte interface [36,37]. The CPE distributed element was introduced for dispersive characteristics of the interfacial capacitance [38,39]. The resistance R2, in parallel with the constant phase element CPE2, is associated with impedance between the glass substrate and TiO2 film [40]. The best-fitted values for the equivalent circuit were given by
Rs = 4 Ω, R1 = 500 Ω, CPE1 = 100 pF, R2 = 100 Ω, CPE2 = 300 pF.

3.5.3. Incident Photon-to-Current Conversion Efficiency (IPCE) Spectra of TiO2-Based DSSC

The IPCE spectrum was plotted in the 350-800 nm wavelength range for the DSSC prepared with undoped and Pt-doped TiO2 nanocomposite, and it is depicted in Figure 10.
IPCE (%) is the ratio of the intensity of the output photon to that of the incident photon.
IPCE (%) = 1240 × Jsc/λPi
Figure 10 shows that our prepared DSSC worked in the visible region of the solar spectrum by transferring the energy from dye to TiO2 through Pt, which increased the overall photocatalytic activity. The maximum IPCE peak of 80% occurred at a wavelength of 550 nm [41,42]. When the IPCE spectra of the undoped versus Pt-doped sample were compared, we found that the sample doped with a high concentration of Pt had the highest IPCE values compared to the undoped sample. The IPCE value for 0.45 M Pt was 78%, while that of the undoped sample was only 60%. This means that the sample doped with 0.45 M Pt was most effective in collecting light radiation. After absorption through N719 dye, it quickly transferred an electron to the counter electrode than the other doped samples. The net contribution can be viewed as a lower bandgap, reduction of series resistance, a high value of short circuit current density, open circuit voltage capabilities, and high dye adsorption favoring the improvement of performance of DSSC. Thus, we found that the 0.45 M Pt-doped sample was the best suited for photoanode material and therefore promotes cell performance.

3.5.4. The Adequate Thickness of Semiconducting Layers at the Photoanode

Three different semiconductor layers were synthesized, namely, 12 μm, 16 μm, and 20 μm during the synthesis process, which was used as a photoanode. The thickness of the film was measured using a surface profiler.
The current–voltage characteristic curve of Figure 11 shows that the short circuit current increased with the decrease in thickness. The value of current density was found to be 13 mA/cm2 for a sample thickness of 12 μm (at a higher doping ratio), 12 mA/cm2 for a sample thickness of 16 μm (at an average ratio), and 10.1 mA/cm2 for a sample thickness of 20 μm (at an average ratio). Thus, thinner thickness and high ratio can promote cell performance. This high current density was due to the high adsorption of N719 dye. Thus, N719 dye had a higher stability than Ru-based N749 and N3 dye [43,44,45,46].
Figure 12 depicts the IPCE spectrum in the wavelength range 350–800 nm for the DSSC prepared with different thicknesses of photoanode. The maximum IPCE peak value of 75% occurred at a wavelength of 520 nm [47,48,49]. The IPCE (%) value was much higher for the sample with a thinner thickness and high molar ratios, which revealed that the sample was more efficient in collecting photo-excited electrons.

4. Conclusions

In this manuscript, we report the synthesis of TiO2 nanoparticles using different Pt concentrations varying from 0.15 M Pt to 0.45 M Pt. Various optical and electrical methods fully characterized the prepared substances. We found that the high molar ratios of Pt doping and thinner thickness of semiconducting layers at the anode significantly contributed to promoting cell performance. Three different semiconductor layers were synthesized, namely, 12 μm, 16 μm, and 20 μm during the synthesis process. The thickness of the film was measured using a surface profiler. The high current density of the cell was due to the high adsorption of N719 dye. The current–voltage characteristic curve revealed that the short circuit current increased with the decrease in thickness and high ratio of Pt doping. The thinner thickness and a high ratio of doping can promote cell performance. Statistical data obtained from optical and electrical investigations revealed that the electrical power–output efficiency of our synthesized DSSC was 14.25%. EIS analysis established the decrease in internal resistance at the electrolyte interface. It could be one of the reasons for the increase in electron transfer rate and decrease in the recombination process at the interface. DSSC has numerous applications in panel display devices and many more optoelectronic devices.

Author Contributions

Conceptualization, M.M. and O.A.A.-H.; Methodology, M.M.; Software, M.M.; Validation, M.M. and O.A.A.-H.; Formal analysis, M.M. and O.A.A.-H.; Investigation, M.M. and O.A.A.-H.; Resources, M.M. and O.A.A.-H.; Data curation, M.M. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

The data supporting this study’s findings were available from the corresponding author.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Grätzel, M. Molecular photovoltaics that mimics photosynthesis. Pure Appl. Chem. 2001, 73, 338–344. [Google Scholar] [CrossRef] [Green Version]
  2. Haque, M.M.; Muneer, M.; Bahnemann, D.W. Semiconductor mediated photocatalyzed degradation of a herbicide derivative, Chlorotoluron, in an aqueous suspension. Environ. Sci. Technol. 2006, 40, 4765–4770. [Google Scholar] [CrossRef] [PubMed]
  3. Paschoalino, F.C.S.; Paschoalino, M.P.; Jordão, E.; de Figueiredo, J.W. Evaluation of TiO2, ZnO, CuO, and Ga2 O3 on the photocatalytic degradation of phenol using an annular flow photocatalytic reactor. Open J. Phys. Chem. 2012, 2, 135–140. [Google Scholar] [CrossRef] [Green Version]
  4. Ba-Abbad, M.M.; Kadhum, H.A.A.; Mohamad, A.B.; Takriff, M.S.; Sopian, K. The effect of process parameters on the size of ZnO nanoparticles synthesized via the sol-gel. J. Alloys Compd. 2013, 550, 63–70. [Google Scholar] [CrossRef]
  5. Wang, H.; Baek, S.; Song, J.; Lee, J.; Lim, S. Microstructural and optical characteristics of solution-grown Ga-doped ZnO nanorod arrays. Nanotechnology 2008, 19, 075607–075612. [Google Scholar]
  6. Anandan, S. Recent improvement and rising challenges in DSSC. Sol. Energy Mater. Sol. Cells 2007, 91, 843–846. [Google Scholar] [CrossRef]
  7. Hsin-Hung, O.; Shang-Lien, L. Effect of Pt/Pd doped TiO2 on the photocatalytic degradation of trichloroethylene. J. Mol. Cat. A Chem 2007, 275, 200–205. [Google Scholar]
  8. Aga, K.W.; Efa, M.T.; Beyene, T.T. Effects of Sulfur doping and temperature on the energy bandgap of ZnO nanoparticles and their antibacterial activities. ACS Omega 2022, 7, 10796–10803. [Google Scholar] [CrossRef]
  9. Zhi, M.; Zhu, L.; Ye, Z.; Wang, F.; Zhao, B. Preparation and properties of ternary ZnMgO nanowires. J. Phys. Chem. B 2005, 109, 23930–23934. [Google Scholar] [CrossRef]
  10. Hembram, K.; Sivaprahasam, D.; Rao, T.N. Combustion synthesis of doped nanocrystalline ZnO powders for varistors applications. J. Eur. Ceram. Soc. 2011, 31, 1905–1913. [Google Scholar] [CrossRef]
  11. Wang, R.C.; Liu, C.P.; Huang, J.L.; Chen, S.J. Single-crystalline Al ZnO nanowires/nanotubes synthesized at low temperature. Appl. Phys. Lett. 2006, 88, 0231. [Google Scholar]
  12. Gupta, A.; Joeri, F.M.D. Hydrogen clathrates: Next generation hydrogen storage materials. Energy. Stor. Maters 2021, 41, 69–107. [Google Scholar]
  13. Rashad, M.; Tekin, H.; Zakaly, H.M.; Pyshkina, M.; Issa, S.A.; Susoy, G. Physical and nuclear shielding properties of newly synthesized magnesium oxide and zinc oxide nanoparticles. Nucl. Eng. Technol. 2020, 52, 2078–2084. [Google Scholar] [CrossRef]
  14. Song, Q.; Zhang, Z.J. Shape control and associated magnetic properties of spinel cobalt errite nanocrystals. J. Am. Chem. Soc. 2009, 126, 6164–6168. [Google Scholar] [CrossRef]
  15. Verma, A.; Khan, F.; Kar, D.; Chakravarty, B.C.; Singh, S.N.; Husain, M. Sol-gel derived aluminum-doped zinc oxide for application as anti-reflection coating in terrestrial silicon solar Cells. Thin Sol. Films 2010, 518, 2649–2653. [Google Scholar] [CrossRef]
  16. Ogi, T.; Hidayat, D.; Iskandar, F.; Purwanto, A.; Okuyama, K. Direct synthesis of highly crystalline transparent conducting oxide nanoparticles by low-pressure spray pyrolysis. Adv. Powder Technol. 2009, 20, 203–209. [Google Scholar] [CrossRef]
  17. Maiyalagan, T.R.; Das, S.J. Optical studies of nano-structured La-doped ZnO prepared by combustion method. Mat. Sci. Semicond. Process. 2012, 15, 308–313. [Google Scholar]
  18. Anandan, S.; Vinu, A.; Lovely, K.L.P.S.; Gokulakrishnan, N.; Srinivasu, P.; Mori, T.; Murugesan, V.; Sivamurugan, V.; Ariga, K. Photocatalytic activity of La-doped ZnO for the degradation of monocrotophos in aqueous suspension. J. Mol. Catal. A Chem. 2007, 266, 149–157. [Google Scholar] [CrossRef]
  19. Meyer, B.K.; Alves, H.; Hofmann, D.M.; Kriegseis, W.; Forster, D.; Bertram, F.; Christen, J.; Hoffmann, A.; Straßburg, M.; Dworzak, M.; et al. Bound exciton and donor-acceptor pair recombinations in ZnO. Phys. Status Solidi B 2004, 241, 231–260. [Google Scholar] [CrossRef]
  20. Korake, P.V.; Dhabbe, R.S.; Kadam, A.N.; Gaikwad, Y.B.; Garadkar, K.M. Highly active lanthanum doped ZnO nanorods for photodegradation of metasystem. J. Photochem. Photobiol. B Biol. 2014, 130, 11–19. [Google Scholar] [CrossRef]
  21. Lieber, C.M. One dimensional nanostructures: Chemistry, Physics and Applications. Solid State Commun. 1998, 107, 6164–6168. [Google Scholar] [CrossRef]
  22. Chih-Hung, T.; Chia-Ming, L.; Yen-Cheng, L. Increasing the efficiency of DSSC by adding Nickel Oxide nanoparticles by adding TiO2 working electrodes. Coatings 2020, 10, 195. [Google Scholar]
  23. Chen, Z.; Cai, Y.; Lu, Y.; Cao, Q.; Lv, P.; Zhang, Y.; Liu, W. Preparation and Performance study of Carboxyl- functionalized graphene oxide composite polyaniline based water composite Epoxy Zinc- rich Coatings. Coatings 2022, 12, 824. [Google Scholar] [CrossRef]
  24. Jasim, K.I. Dye-sensitized solar cells—Working principles, challenges, and opportunities. Solar cells—Dye-Sensitized Devices; Kosyachenko, L.A., Ed.; Intech Open: London, UK, 2011. [Google Scholar]
  25. Tang, Z.; Kotov, N.A.; Giersig, M. Spontaneous organization of single CdTe nanoparticles into luminescent nanowires. Science 2002, 297, 237–240. [Google Scholar] [CrossRef] [PubMed]
  26. Rosario, A.V.; Pereira, E.C. The role of Pt addition on the photocatalytic activity of TiO2 nanoparticles: The limit between doping and metallization. App. Catal. B Environ. 2014, 144, 840. [Google Scholar] [CrossRef]
  27. Garcia, R.; Tello, M. Size and shape controlled growth of molecular nanostructures on silicon oxide templates. Nano Lett. 2004, 4, 1115–1119. [Google Scholar] [CrossRef]
  28. Chunqiao, G.; Changsheng, X.; Mullin, H.; Shanghai, G.; Zikui, B.; Dawen, Z. Structural characteristics, and UV-light enhanced gas sensitivity of La-doped ZnO Nanoparticles. Mater. Sci. Eng. B 2007, 141, 43–48. [Google Scholar]
  29. Cheng, H.C.; Chen, C.F.; Tsay, C.Y. Transparent ZnO thin-film transistor fabricated by sol-gel and chemical bath deposition combination method. Appl. Phys. Lett. 2007, 90, 012113. [Google Scholar] [CrossRef] [Green Version]
  30. Sahay, P.P.; Nath, R.K. Al-doped zinc oxide thin films for liquid petroleum gas (LPG) sensors. Sens. Actuators B 2008, 133, 222–227. [Google Scholar] [CrossRef]
  31. Hoyer, P. semiconductor nanotube formation by a two-step template process. Adv. Mater. 1996, 8, 857–859. [Google Scholar] [CrossRef]
  32. Yang, J.H.; Bark, C.W.; Kim, K.H.; Choi, H.W. Characterization of the DSSC using TiO2 nanotubes treated with TiCl4. Materials 2014, 7, 3522–3532. [Google Scholar] [PubMed]
  33. Ali, M.K.M.E.; Ali, S.M.U.; Hashim, U. Sol-gel synthesis of Pd doped ZnO nanorods for room temperature hydrogen sensing applications. Ceram. Int. 2013, 39, 6461–6466. [Google Scholar]
  34. Liu, Z.; Liu, C.; Ya, J.; Lei, E. Controlled synthesis of ZnO and TiO2 nanotubes by chemical method and their application in dye-sensitized solar cells. Renew. Energy 2011, 36, 1177–1181. [Google Scholar] [CrossRef]
  35. Serier, H.; Gaudon, M.; Menetrier, M. Al-doped ZnO powdered materials: Al solubility limit and IR absorption properties. Solid State Sci. 2009, 11, 1192–1197. [Google Scholar] [CrossRef]
  36. Zhong, J.B.; Li, J.Z.; He, X.Y.; Zeng, J.; Lu, Y.; Hu, W.; Lin, K. Improved photocatalytic performance of Pd-doped ZnO. Curr. Appl. Phys. 2012, 12, 998–1001. [Google Scholar] [CrossRef]
  37. González-Hernández, R.; López-Pérez, W.; Rodríguez, M.J.A. Magnetic ordering and electronic properties of Pd-doped ZnO. Phys. Status Solidi B 2012, 249, 198–201. [Google Scholar] [CrossRef]
  38. Assadi, M.H.N.; Zhang, Y.; Zheng, R.-K.; Ringer, S.P.; Li, S. Structural and electronic properties of Eu- and Pd-doped ZnO. Nanoscale Res. Lett. 2011, 6, 357. [Google Scholar]
  39. Han, Z.; Li, S.; Chu, J.; Chen, Y. Electrospun Pd-doped ZnO nanofibers for enhanced photocatalytic degradation of methylene blue. J. Sol-Gel Sci. Technol. 2013, 66, 139–144. [Google Scholar] [CrossRef]
  40. Lin, J.; Yu, J.C.; Lo, D.; Lam, S.K. Photocatalytic activity of rutile Ti1-x Sex O2 solid solutions. J. Catal. 1999, 183, 368–372. [Google Scholar] [CrossRef]
  41. Stengl, V.; Bakardjieva, S.; Murata, N. Preparation and photocatalytic activity of rare-earth-doped TiO2 nanoparticles. Mater. Chem. Phys. 2009, 114, 217–226. [Google Scholar] [CrossRef]
  42. Saif, A.A.; Ajamal, Z.; Sauli, Z.; Poopalan, P. Frequency-Dependent Electrical Properties of Ferroelectric Ba0.8 Sr0.2 TiO2 thin Film. Mater. Sci. 2011, 17, 186–190. [Google Scholar]
  43. Stengl, V.; Bakardjieva, S. Molybdenum-doped anatase and its extraordinary photocatalytic activity in the degradation of orange II in the UV and Vis regions. J. Phys. Chem. C 2010, 114, 19308–19317. [Google Scholar] [CrossRef]
  44. Gafoor, A.K.A.; Thomas, J.; Mustafa, M.M.; Pradyumnan, P.P. Effect of Sr3+ Doping on dielectric properties of Anatase TiO2 Nanoparticles synthesized by a low-temperature hydrothermal method. J. Electron. Mater. 2011, 40, 2152–2158. [Google Scholar] [CrossRef]
  45. Subashini, G.; Andrews, N.G. Titanium nitride nanoflower buds as Pt-free counter electrodes for dye-sensitized solar cells. Appl. Nano lett. 2021, 4, 8251–8261. [Google Scholar]
  46. Liqiang, J.; Xiaojun, S.; Baifu, X.; Baiqi, W.; Weimin, C.; Hongganga, F. The preparation and characterization of La-doped TiO2 nanoparticles and their photocatalytic activity. J. Solid State Chem. 2004, 177, 3375–3382. [Google Scholar] [CrossRef]
  47. Manarola, M.H.; Parmar, B.H.; Pillai, A.S.; Joshi, V.S. Structural Optical and Electrical properties of Titanium Dioxide Nanoparticle. Multi-Discip. Edu Glob. Quest 2012, 1, 138–145. [Google Scholar]
  48. Prodromakis, T.; Papavassiliou, C. Engineering the Maxwell-Wagner polarization effect. Appl. Surf. Sci. 2009, 255, 6989–6994. [Google Scholar] [CrossRef]
  49. Jeeevanandan, J.; Barhoum, A.; Chan, Y.S.; Dufresne, A. Review on nanoparticles and nanostructured materials; history, sources, Toxicity, and Regulations. Best J. Nanotechnol. 2018, 9, 1050–1074. [Google Scholar]
Materials 15 07941 g001 550
Figure 1. Schematic of TiO2-based DSSC.
Figure 1. Schematic of TiO2-based DSSC.
Materials 15 07941 g001
Materials 15 07941 g002 550
Figure 2. XRD patterns of undoped TiO2 and Pt-doped TiO2 at different molar concentrations; calcination temp: 400 °C, calcination time: 16 h.
Figure 2. XRD patterns of undoped TiO2 and Pt-doped TiO2 at different molar concentrations; calcination temp: 400 °C, calcination time: 16 h.
Materials 15 07941 g002
Materials 15 07941 g003 550
Figure 3. Absorption spectra of undoped TiO2 and Pt-doped TiO2 at different molar concentrations.
Figure 3. Absorption spectra of undoped TiO2 and Pt-doped TiO2 at different molar concentrations.
Materials 15 07941 g003
Materials 15 07941 g004 550
Figure 4. Band gap calculation using the Tauc method.
Figure 4. Band gap calculation using the Tauc method.
Materials 15 07941 g004
Materials 15 07941 g005 550
Figure 5. TEM images of Pt-doped TiO2.
Figure 5. TEM images of Pt-doped TiO2.
Materials 15 07941 g005
Materials 15 07941 g006 550
Figure 6. EDS spectra of nanocomposite material.
Figure 6. EDS spectra of nanocomposite material.
Materials 15 07941 g006
Materials 15 07941 g007 550
Figure 7. Current density versus photovoltage of undoped TiO2 and Pt-doped TiO2 at different molar concentrations.
Figure 7. Current density versus photovoltage of undoped TiO2 and Pt-doped TiO2 at different molar concentrations.
Materials 15 07941 g007
Materials 15 07941 g008 550
Figure 8. Nyquist plot of undoped TiO2 and Pt-doped TiO2 at different molar concentrations.
Figure 8. Nyquist plot of undoped TiO2 and Pt-doped TiO2 at different molar concentrations.
Materials 15 07941 g008
Materials 15 07941 g009 550
Figure 9. Equivalent circuit of the DSSC.
Figure 9. Equivalent circuit of the DSSC.
Materials 15 07941 g009
Materials 15 07941 g010 550
Figure 10. IPCE spectra of undoped and Pt-doped TiO2 at different molar concentrations.
Figure 10. IPCE spectra of undoped and Pt-doped TiO2 at different molar concentrations.
Materials 15 07941 g010
Materials 15 07941 g011 550
Figure 11. Current density versus photovoltage at three different thicknesses and molar ratios.
Figure 11. Current density versus photovoltage at three different thicknesses and molar ratios.
Materials 15 07941 g011
Materials 15 07941 g012 550
Figure 12. IPCE spectra at three different thicknesses and molar ratios.
Figure 12. IPCE spectra at three different thicknesses and molar ratios.
Materials 15 07941 g012
Table
Table 1. Electrical and optical parameters of DSSC.
Table 1. Electrical and optical parameters of DSSC.
% Pt Content
(M)		IPEC
Peak (%)		JSC
(mA/cm2)		(Voc)
(volt)		FEfficiency
(%)
Undoped TiO260110.750.541.45
TiO2 doped with 0.15M Pt7012.50.720.594.25
TiO2 doped with 0.25 M Pt7213.10.860.695.22
TiO2 doped with 0.35 M Pt7516.50.920.7911.92
TiO2 doped with 0.45 M Pt7817.50.960.8914.25
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Share and Cite

MDPI and ACS Style

Mujahid, M.; Al-Hartomy, O.A. The Effects of Pt-Doped TiO2 Nanoparticles and Thickness of Semiconducting Layers at Photoanode in the Improved Performance of Dye-Sensitized Solar Cells. Materials 2022, 15, 7941. https://doi.org/10.3390/ma15227941

AMA Style

Mujahid M, Al-Hartomy OA. The Effects of Pt-Doped TiO2 Nanoparticles and Thickness of Semiconducting Layers at Photoanode in the Improved Performance of Dye-Sensitized Solar Cells. Materials. 2022; 15(22):7941. https://doi.org/10.3390/ma15227941

Chicago/Turabian Style

Mujahid, M., and Omar A. Al-Hartomy. 2022. "The Effects of Pt-Doped TiO2 Nanoparticles and Thickness of Semiconducting Layers at Photoanode in the Improved Performance of Dye-Sensitized Solar Cells" Materials 15, no. 22: 7941. https://doi.org/10.3390/ma15227941

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop