Fluorine-doped Tin Oxide Glass Research Articles

Titanium dioxide/cadmium sulfide photoanode applied to photoelectrodegradation of naproxen in wastewater

• The application of photoelectrochemical method increased the catalytic response. • Photosensitization contributed to avoid recombination of e − /h + charges. • The EC involved is relatively inexpensive for removing 1.0 kg of NPX using the PEC method. In this work TiO 2 and CdS were synthesized, characterized, and applied on the fabrication of photoanodes for degradation of naproxen in aqueous matrices. The photoanodes were based on the deposition of the TiO 2 film over fluorine-doped tin oxide glass plates followed by a CdS electrodeposition film. Characterizations of the photoanodes were performed by linear sweep voltammetry, transmission electronic microscopy, energy-dispersive X-ray spectroscopy, and diffuse reflectance spectroscopy. The degradation process of naproxen was evaluated using UV–vis spectroscopy and total organic carbon. The CdS presented a low energy band gap, resulting in the increase of the photocurrent generated in the photoanode. The proposed photoanode showed efficiency for the photoelectrochemical degradation of naproxen with kinetic constant estimated at k = 1.1 × 10 −2 min −1 and t 1/2 = 62.2 min −1 .

Thermally evaporated CdS thin films for CdS/CdTe solar cells: Effect of substrate temperature on CdS layer

CdS thin films were deposited by vacuum thermal evaporation technique on Fluorine-doped Tin Oxide glass substrates at different substrate temperatures ranging from 50 to 250 °C. Post deposition heat-treated thin films were characterized for optical, structural, morphological and electrical properties to study the dependence substrate temperature. The optical bandgap was found in the range of 2.42–2.46 eV. Crystallite size, microstrain, phase distribution, and lattice parameters were calculated using x-ray diffractogram profile fit, Rietveld and Pawley refinement techniques. Best electrical properties of photoelectrochemical cells were observed for the films grown at a substrate temperature of 175 °C. CdS/CdTe full cells were fabricated using thermal evaporation technique and the highest efficiency of 3.76% and highest external quantum efficiency of 70% were observed for the CdS thin film grown at a substrate temperature of 175 °C and the variation was confirmed with SCAPS-1D simulation.

Copper Oxide Decorated Zinc Oxide Nanostructures for the Production of a Non-Enzymatic Glucose Sensor

The glucose concentration in human blood can have a worrisome impact on human health, so the distribution of blood glucose contaminants in the human body is an important indicator that can be used to monitor diabetes. Diabetes affects many parts of the human body, such as neurological impairment, erectile dysfunction, and hardening of the arteries resulting in organ loss. In this study, cyclic voltammetry (CV) was used to process the electrical properties of a solution by preparing electrodes with CuO nanoparticles modified ZnO tetrapod nanostructures deposited on fluorine-doped tin oxide glass (CuO/ZnO/FTO). The measurements were processed in glucose solutions of different concentrations purposing for developing the sensitivity of the sensor. Different immersion times in the precursor copper sulfate solution were also used for preparing the electrode and carried out for electrochemical studies to adjust the electrode capability. The modified electrode, which was immersed in copper sulfate for 30 s, was efficient in detecting glucose molecules in different concentrations at the potential of +0.6 V. The rising slope is strongly and positively correlated with the concentration of glucose. One of the significant results is the indication that glucose concentration is linearly proportional to the current value of CV. After the measurement test with the addition of interference, the sensor can still identify the glucose concentration in the solution without being affected. This result proves that the sensor has considerable potential for developing into a high-performance non-enzymatic glucose sensor.

Structural, morphological, optical and photoelectrochemical properties of ZnFe2O4 thin films grown via an electrodeposition method

Various zinc ferrite (ZnFe2O4) nanostructures were successfully synthesized by an environmentally-friendly, facile, cost-effective and simple one-step electrodeposition method. ZnFe2O4 film on fluorine-doped tin oxide glass (FTO) were prepared at different times (10 s, 40 s, 60 s, 120 s, 180 s) by electrodeposition method. The phase structural, morphological and the photoelectrochemical (PEC) properties are studied by using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), linear sweep voltammetry (LSV), chronoamperometry (CA) and open circuit potential (OCP). Ultraviolet–visible (UV–Vis) diffuse reflection spectroscopy was performed to study band gap and optical absorption properties. Based on the experimental results, the maximum amount of photocurrent was taken from the sample with an electrodeposition time of 60 s. The precipitate was removed from the FTO surface as longer exposure time was applied. Electrodeposition time changes the morphological properties of the surface as a result increasing the deposition time, the sheet-like nanostructures were formed.

Photovoltaic and impedance properties of dye-sensitized solar cell based on nature dye from beetroot

The present study involves fabrication and photovoltaic characterization including impedance properties of dye-sensitized solar cells based on natural dye from beetroot. The electrode of the cell was prepared with commercial Fluorine-doped Tin Oxide glass with 100 μm layer of nanostructured TiO2 whereas, the counter electrode consisted of platinum-coated glass. Fresh juice was extracted from beetroot to use as dye. The dye exhibited high absorption in visible range. Photovoltaic measurements of the solar cell gave a short circuit current density (Jsc) of 130 μA/cm2 and an open-circuit voltage (VOC) of 0.38 V under AM 1.5 illumination intensity. The VOC and Jsc showed linear behavior at higher values of illumination intensities. The conductance-voltage, the capacitance-voltage and the series resistance voltage characteristics of the dye solar cell was measured at frequency range from 5 kHz to 5 MHz to study performance of the dye-sensitized solar cells with natural dyes.

Hierarchical FTO/PPy/ACo2O4 (A: Mn or Ni) with stacks spinel structure as superb photoanodes for photoelectrochemical water splitting

Herein, the manganese (Mn) and nickel (Ni) doped cobalt oxide (Co3O4) with stacks spinel structure were incorporated on the polypyrrole (PPy)- coated Fluorine-doped tin oxide (FTO) glasses to improve oxygen evolution reaction (OER) efficiencies in PEC water splitting. We designed such a heterostructure configuration as an ideal model to understand the impact of the.MnCo2O4 and NiCo2O4 on the photoelectrocatalytic performances. Results showed that the FTO/PPy/NiCo2O4 possess superior photocurrent density (11.37 mA cm−2) compared to the FTO/PPy/Co3O4 (7.26 mA cm−2), and FTO/PPy/MnCo2O4 (9.16 mA cm−2) at 1.23 V vs. reverse hydrogen electrode (RHE). Moreover, the electrochemical surface area (ECSA) of the FTO/PPy/NiCo2O4 was obtained 1.4 and 1.8-folds higher than those considered for the FTO/PPy/MnCo2O4 and FTO/PPy/Co3O4, respectively. Specific spinel configuration of NiCo2O4 on PPy films provided the highest ECSA to access the carrier charge and their contribution in the redox reaction. The highest value of the O2 (5.256 μmol. h−1) was exuded from the surface of the FTO/PPy/NiCo2O4 by 2.5 and 1.8 orders of magnitude compared to those estimated for FTO/PPy/Co3O4, FTO/PPy/MnCo2O4.

Electrical Characterization and Efficiency Enhancement of Dye Sensitized Solar Cell Using Natural Sensitizer and TiO2 Nanoparticles Deposited by Electrophoretic Technique

This article concerns the use of anthocyanin, mallow and their mixture as a low-cost natural dyes to sensitize the photo-anodes of dye sensitized solar cells (DSSCs) based on titanium dioxide (TiO2) layers, and investing their effect on the electrical performance of the realized cells. In fact, different layers of porous titanium dioxide (TiO2) were deposited on fluorine-doped tin oxide glass (FTO) via the electrophoretic deposition (EPD) technique, and then sensitized with natural dyes to form the photo-anode electrode for the DSSC. Four DSSCs are manufactured: three cells, each one is formed by a TiO2 single layer and a cell formed by two TiO2 layers. An electric model, with five parameters based on of the Newton–Raphson algorithm (NR), was used to extract the electrical parameters of the cell and establish a comparative study between simulated and experimental current–voltage characteristic ( J – V ). An improvement of short-circuit current and efficiency was obtained for the DSSC with two layers of TiO2 and sensitized with the mixture of mallow and anthocyanin. Indeed, an increase of short circuit current from 0.34 to 1.98 mA/cm2 was observed and the efficiency reached 0.58%. This increase was more confirmed by external quantum efficiency (EQE). Nevertheless, after 96 hours under standard lighting at room temperature of 25 °C, a degradation of the efficiency of the cell with a rate value of 24% was noted.

Techno-economic assessment of titanium dioxide nanorod-based perovskite solar cells: From lab-scale to large-scale manufacturing

Perovskite solar cells (PSCs) have shown remarkable progress in recent years. Different materials and structures have been developed to improve the photoconversion efficiency and operational stability of PSCs. However, the economic and technical impacts of materials and design choice on the large-scale deployment are not well addressed in the literature. In this research, a pathway for producing titanium dioxide (TiO2) nanorod-based perovskite solar modules was established and their manufacturing cost was estimated through the development of data-intensive, bottom-up techno-economic models. Material, utilities, and equipment requirements from available laboratory data to a mass production annual capacity of up to 21 MW were estimated through the development of scale factors. The minimum sustainable price and levelized cost of electricity were calculated. The direct manufacturing cost of the reference PSC module was estimated at $80.23/m2 and $0.73/W with a production capacity of 3.5 MWp. These costs decline to $47.15/m2 and $0.43/W at 21 MW production capacity. Material costs dominate the overall costs, fluorine-doped tin oxide glass being the most expensive material. The perovskite solar cell panels, when installed in residential homes in Alberta, Canada, were calculated to have a competitive levelized cost of electricity ranging from 7 to 17 cents per kWh. However, the cost was found to be extremely sensitive to the module efficiency, lifetime, and the solar insolation at the location of installation.

Band gap narrowing and prolongation of carrier lifetime in solution-processed CeO2/CdS thin films for application as photoanodes in quantum dot sensitized solar cells

Band gap energy of more than 3.5 eV for CeO2 nanostructures restricts their efficacies in visible light harvesting. But, reduction in the optical band gap and efficient separation of photogenerated charge carriers can be achieved by forming heterojunction of CeO2 with suitable narrow band gap semiconductors such as CdS and CdSe. In this way, the energy application of CeO2 nanostructured thin films can be extended to visible region of the electromagnetic spectrum. For the above purpose, we deposited CeO2/CdS nanocomposite thin films on fluorine-doped tin oxide (FTO) glass substrates by sol-gel spin coating followed by chemical bath deposition (CBD) process. The structure, phase, morphology, surface topography, as well as interface charge transfer dynamics of the nanocomposites were systematically investigated by various characterization techniques. The CeO2/CdS thin films with CdS bath deposition time of 60 min showed a polydispersity index of 0.19 with an average particle size of 8.8 nm. The observed band gap for one of the CeO2/CdS thin films was 2.19 eV which was well below the bulk band gap for CeO2. The prolongation of carrier lifetime (~8.24 μs) in CeO2/CdS thin film was established from photoluminescence decay analysis. The dominance of radiative recombination in the nanocomposite implies a reduction in the rate of non-radiative re-combinations. This situation favors the separation of more number of e--h+ pairs. The interface formed between the two phases facilitates transportation of separated carriers. An enhancement in the electrical conductivity of the CeO2 occurred when a surface CdS layer was added. A narrowed band gap, prolonged carrier lifetime, and improved electrical conductivity of CeO2/CdS films may lead to enhanced charge transportation ability. The significant values of Jsc and Voc obtained from the photoelectrochemical solar cell measurements prove that CeO2/CdS thin films are suitable for photovoltaic applications.

Sulphate Radical Enhanced Photoelectrochemical Degradation of Sulfamethoxazole on a Fluorine Doped Tin Oxide - Copper(I) Oxide Photoanode

We report a sulphate radical enhanced photoelectrochemical degradation of sulfamethoxazole on a solar light driven fluorine doped tin oxide - copper(I) oxide photoanode. Copper(I) oxide was prepared by a template-free method and dispersed onto the surface of a fluorine doped tin oxide glass to form the photoanode. UV-Vis diffuse reflectance spectroscopy showed that the photoanode absorbed in the visible light region. With sodium persulphate as the source of sulphate radical, photoelectrochemical degradation studies showed that sodium persulphate markedly enhanced the degradation of sulfamethoxazole. Studies on the effects of change in concentration of the persulphate and the absence of the persulphate on the photoelectrocatalytic degradation process were conducted. Overall, the extent of degradation and mineralisation of sulfamethoxazole in water was found to be 86% and 67% respectively with bias potential of 1.5 V for the sulphate radical enhanced process. Scavenger studies showed that the photogenerated holes and sulphate radicals were the primary active species in the abatement of sulfamethoxazole.

Experimental investigation of dye sensitized solar cells, formed with obtaining thin films by using undoped and Nb‐doped TiO 2 precursors

In this study, the effect of the working electrode obtained by using different methods and chemicals on the efficiency of dye-sensitized solar cells (DSSC) is examined. The aim here is to carry out the undoped and metal-doped TiO2 deposition process by the ultrasonic spray pyrolysis (USP) method. Titanium dioxide (TiO2) semiconductor is selected to form the working electrode and Niobium (Nb) is used for metal doping. The working electrode is obtained by spraying the previously prepared undoped and Nb-doped TiO2 solution onto fluorine-doped tin oxide (FTO) glass by USP Technique. The working electrodes obtained are used to fabricate DSSC. XRD, SEM, and EDS analyses are performed to examine the surface morphology, crystal structure, and elemental properties of conductive glasses. By assembling the components as a sandwich, two different cells are formed. The efficiency of the cell which has an undoped TiO2 thin film is 0.088%, and the efficiency of the cell which has Nb-doped TiO2 thin film is 0.375%. These results proved that the doped cell is more efficient than the undoped cell and that it can be produced more economically.

Nanostructured FeS2 films: Influence of effective parameters on electrochemical deposition and characterization of physical properties

In this study, films of iron disulfide (FeS2) nanostructures are prepared by electrochemical deposition on the Fluorine-doped tin oxide (FTO) glass substrate. The effect of deposition parameters such as voltage, time, molarity, and also sulfurization temperature are studied as parameters affecting the physical properties of the deposited films. The prepared films are studied and characterized by analysis of X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), Raman spectroscopy, photoluminescence (PL), and UV–Vis–NIR spectroscopy. Following sulfurization, the XRD analysis shows the cubic phase of pyrite. The phase purity of the prepared samples are confirmed by Raman spectroscopy and the presence of Fe and S elements is verified by EDX analysis. The micrograph of FESEM shows that different morphologies in porous, spherical, and flower-like forms in nanometer dimensions are obtained by changing the effective parameters. The PL spectrum shows the presence of emission bands in the visible region. With the increase in the sulfurization temperature, the light absorption intensity of the films increases and the energy band gap increases from 1.53 to 1.73 eV, confirmed by UV–Vis–NIR spectroscopic analysis. The Mott-Schottky's analysis shows the p-type conductivity. Based on the results, the amount of photosensitivity, photoresponsivity, and specific detectivity increases with the rise in temperature. The sample sulfurized at 250 °C, compared to the sample sulfurized at 200 °C, shows a remarkable photoresponsivity in the range of visible spectrum. The values of photoresponsivity, photosensitivity, and specific detectivity at 100 mW/cm2 intensity are 22.7 mA/W, 18.80%, and 0.37×109 (Jones), respectively. According to the obtained results, this material has the potential for use in the fabrication of high-efficiency optoelectronic devices.

Fluorine-surface-modified tin-doped hematite nanorod array photoelectrodes with enhanced water oxidation activity

Severe charge recombination and sluggish water oxidation reaction (OER) kinetics significantly limit the practical application of hematite in photoelectrochemical (PEC) water-splitting devices. In this study, fluorine-surface-modified tin-doped hematite (F/Sn:Fe2O3) photoelectrodes have been fabricated by a hydrothermal method incorporated impregnation annealing process. The grown FeOOH nanorods coated with NH4F solution are annealed first at 550 °C in the vacuum to modify the hematite surface and then at 750 °C in argon to promote the diffusion of tin atoms from the fluorine-doped tin oxide (FTO) glass substrate to the hematite structure. The synergistic effect of F-modification and Sn-doping on Fe2O3 electrode considerably enhances its PEC water oxidation performance, resulting in the highest photocurrent density of 3.64 mA cm−2 at 1.23 V vs. reversible hydrogen electrode (RHE) under AM 1.5 G illumination. Both effects increase the carrier concentration in the photoelectrode, which improves its transport efficiency. Moreover, the surface-localized F species promote the OER process on the electrode surface and improve the charge separation at the electrode/electrolyte interface by increasing its hole supply rate under the increased electric field. This work may open a new avenue for fabricating novel photoelectrodes with high PEC water splitting efficiency.

Antimony tin oxide/lead selenide composite as efficient counter electrode material for quantum dot-sensitized solar cells

Antimony tin oxide (ATO)/lead selenide (PbSe) composite was rationally designed and fabricated on fluorine doped tin oxide glass (FTO) for using as counter electrode (CE) of quantum dot sensitized solar cells (QDSSCs). The electrocatalytic activity of the CE is deeply investigated in the polysulfide electrolyte by employing the Tafel, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) of the symmetrical cells. The results confirm that the ATO/PbSe CE has better electrocatalytic activity and stability than that of PbSe CE obtained by pulse voltage electrodeposition (PVD). The enhanced electrocatalytic performance of ATO/PbSe CE can be attributed to its high specific surface area, excellent permeability, conductivity and interface connectivity, which provide more electrocatalytic active sites for the reduction of polysulfide species, as well as fast channels for ions diffusion and electron transport. As a result, the CdS QDSSCs and CdS/CdSe co-sensitized QDSSCs assembled by the ATO/PbSe CE exhibits better power conversion efficiency (η) of 1.72% and 5.59%, respectively than that of PbSe CE obtained by PVD. Furthermore, photovoltaic property of the ATO/PbSe CE in CdS/CdSe co-sensitized QDSSCs keeps stable for over 200 min. This present work provides a simple and effective strategy for the construction of high-performance CE materials of QDSSCs.

Magnesium-doped green solar cells using natural chromophores

The current study tested the hypothesis of whether specific metal doping may show synergy with plant chromophore-based solar cells using a titanium dioxide (TiO2) electrode. A natural dye-sensitized, magnesium-doped TiO2 solar cell was assembled using the methanol extract from various western African plants including Lawsonia inermis (henna). Mg2+–TiO2 nanoparticles were applied on fluorine-doped tin oxide (FTO) glass to serve as the photoanode of the solar cells with $$I^{ - } /I_{3}^{ - }$$ electrolyte. A surface-modified TiO2 photoanode was prepared through the immersion method using a selective dopant including magnesium and potash. An inductively coupled plasma-optical emission spectrophotometer (ICP-OES) was utilized to characterize the potash dopant for comparative analysis. Instrumental analysis including ultraviolet–visible spectroscopy (UV–Vis), infrared spectroscopy (IR), and gas chromatography and mass spectrometry (GC–MS) analysis were carried out to characterize the natural henna dye extracts. The photovoltaic performance including open-circuit voltage (Voc), short circuit current density (Jsc), current (I), and power output (P) was analyzed quantitatively. ICP-OES analysis demonstrated that potash contains a composite of 26 elemental metals with K and Na accounting for 72.2% (5192.2 mg/kg) and 9.5% (682.6 mg/kg), respectively. GC–MS analysis confirmed the presence of lawsone and tocopherol in henna extracts. Among the tested samples, the Mg-doped TiO2 group generated the highest improvement in Jsc, from 0.66 to 1.28 (mA/cm2), representing a 93% increase. Our experiments demonstrated that the presence of magnesium as a doping agent improves the photogenerated electron transport and the light-harvesting performance of the henna dye to increase the overall efficiency of light-to-electricity conversion of the photovoltaic cells.

Cu-doped TiO2 nanoparticles/graphene composites for efficient dye-sensitized solar cells

Graphene (GR) demonstrates excellent photoelectrochemical properties, including its large specific surface area, unique structure, chemical stability, high conductance, and fast electron transfer. These parameters are crucial for the performance improvement and photoanode optimization of a dye-sensitized solar cell (DSSC). In this study, Cu-doped TiO2/graphene (CuTGR) composites have been prepared for the first time by the sol–gel-assisted hydrothermal method for the DSSC photoanode application. The prepared CuTGR composites have been coated on Fluorine-doped tin oxide (FTO) glass substrates using the doctor blade method. The surface morphological and elemental analysis reveals the presence of Cu and graphene into CuTGR nanocomposite with uniform distribution and desired morphology. The addition of graphene further improves the dye loading ability of the CuTGR photoanodes with improved current density and faster charge transport as observed in current–voltage (J-V) and intensity-modulated photocurrent spectroscopy (IMPS) measurements. Our findings demonstrate that an optimal loading of Cu and graphene can boost the power conversion efficiency (PCE) of the DSSC (9.81%) by 47% higher than undoped DSSC (6.66%).

A Hybrid Hole Transport Layer for Perovskite-Based Solar Cells

This paper presents the effect of a composite poly(3,4-ethylenedioxythiophene) polystyrene sulfonate PEDOT:PSS and copper-doped nickel oxide (Cu:NiOx) hole transport layer (HTL) on the performance of perovskite solar cells (PSCs). Thin films of Cu:NiOx were spin-coated onto fluorine-doped tin oxide (FTO) glass substrates using a blend of nickel acetate tetrahydrate, 2-methoxyethanol and monoethanolamine (MEA) and copper acetate monohydrate. The prepared solution was stirred at 65 °C for 4 h and spin-coated onto the FTO substrates at 3000 rpm for 30 s in a nitrogen glovebox. The Cu:NiOx/FTO/glass structure was then annealed in air at 400 °C for 30 min. A mixture of PEDOT:PSS and isopropyl alcohol (IPA) (in 1:0.05 wt%) was spun onto the Cu:NiOx/FTO/glass substrate at 4000 rpm for 60 s. The multilayer structure was annealed at 130 °C for 15 min. Subsequently, the perovskite precursor (0.95 M) of methylammonium iodide (MAI) to lead acetate trihydrate (Pb(OAc)2·3H2O) was spin-coated at 4000 rpm for 200 s and thermally annealed at 80 °C for 12 min. The inverted planar perovskite solar cells were then fabricated by the deposition of a photoactive layer (CH3NH3PbI3), [6,6]-phenyl C61-butyric acid methyl ester (PCBM), and a Ag electrode. The mechanical behavior of the device during the fabrication of the Cu:NiOx HTL was modeled with finite element simulations using Abaqus/Complete Abaqus Environment CAE. The results show that incorporating Cu:NiOx into the PSC device improves its density–voltage (J–V) behavior, giving an enhanced photoconversion efficiency (PCE) of ~12.8% from ~9.8% and ~11.5% when PEDOT:PSS-only and Cu:NiOx-only are fabricated, respectively. The short circuit current density Jsc for the 0.1 M Cu:NiOx and 0.2 M Cu:NiOx-based devices increased by 18% and 9%, respectively, due to the increase in the electrical conductivity of the Cu:NiOx which provides room for more charges to be extracted out of the absorber layer. The increases in the PCEs were due to the copper-doped nickel oxide blend with the PEDOT:PSS which enhanced the exciton density and charge transport efficiency leading to higher electrical conductivity. The results indicate that the devices with the copper-doped nickel oxide hole transport layer (HTL) are slower to degrade compared with the PEDOT:PSS-only-based HTL. The finite element analyses show that the Cu:NiOx layer would not extensively deform the device, leading to improved stability and enhanced performance. The implications of the results are discussed for the design of low-temperature solution-processed PSCs with copper-doped nickel oxide composite HTLs.

Photo-electrochemical water splitting through graphene-based ZnS composites for H2 production

Hydrogen production through photo-electrochemical (PEC) water splitting is obstructed by strong forces of attraction between H2O molecules and charge recombination in semiconductor materials. To overcome such limitations, graphene-based ZnS heterojunction photo-anode is developed that magnifies the PEC performance by improving optical properties and enhancing charge separation. ZnS composites with different weight ratios (2%, 4%, and 6%) of graphene are prepared through the hydrothermal process and characterized by using x-rays diffraction (XRD), transmission electron microscopy (TEM), uv–vis spectroscopy, and x-rays photon spectroscopy (XPS) to obtain crystallinity, morphology, uv–vis spectra and binding energy of prepared materials, respectively. Synergic effect of ZnS composite with 6% weight loading of graphene achieved a notable photo-current density (2.23 mA cm−2 at 0.72 V vs. RHE) under illumination. Moreover, 3.7 folds increased hydrogen yield of 0.049 μmoles cm−2 min−1 by 10 mg mass loading of material on fluorine-doped tin oxide (FTO) glass slide is obtained as compared to pure ZnS with hydrogen yield of 0.049 μmoles cm−2 min−1.

Synthesis of Cobalt Oxide on FTO by Hydrothermal Method for Photoelectrochemical Water Splitting Application

Cobalt oxide thin films were successfully grown directly on fluorine-doped tin oxide glass substrates through a simple, green, and low-cost hydrothermal method. An investigation into the physicochemical characteristics and photoelectrochemical (PEC) properties of the developed cobalt oxide thin film was comprehensively performed. At various annealing temperatures, different morphologies and crystal phases of cobalt oxide were observed. Microflowers (Co3O4) and microflowers with nanowire petals (Co3O4/CoO) were produced at 450 °C and 550 °C, respectively. Evaluation of the PEC performance of the samples in KOH (pH 13), Na2SO4 (pH 6.7), and H2SO4 (pH 1) revealed that the highest photocurrent −2.3 mA cm−2 generated at −0.5 V vs. reversible hydrogen electrode (RHE) was produced by Co3O4 (450 °C) in H2SO4 (pH 1). This photocurrent corresponded to an 8-fold enhancement compared with that achieved in neutral and basic electrolytes and was higher than the results reported by other studies. This promising photocurrent generation was due to the abundant source of protons, which was favorable for the hydrogen evolution reaction (HER) in H2SO4 (pH 1). The present study showed that Co3O4 is photoactive under acidic conditions, which is encouraging for HER compared with the mixed-phase Co3O4/CoO.

The effect of electrodeposition applied potential on the electrochemical performance of polyaniline films

Polyaniline (PANI) has been widely studied and used for the energy storage applications, especially in supercapacitors, this is due to their good pseudocapacitance properties, and it is easy for synthesis. In this study, we describe the effects of the electrodeposition applied potential on the electrochemical performance of polyaniline films. The electrodeposition of PANI films on fluorine-doped tin oxide (FTO) glass substrate is released by chronoamperometry technique using an electrolytic solution containing 0.3 M of aniline in 1 M H2SO4 at different applied potentials (i.e., + 0.8 V, + 0.9 V and + 1 V vs. SCE) for 300 sin time. All prepared films are characterized by different techniques scanning electronic microscopy, infrared spectroscopy, thermogravimetric analysis, and electrical conductivity measurement. For the application, the FTO/PANI films are used as material electrode in supercapacitor. The electrochemical performances are evaluated by cyclic voltammetry, galvanostatic charge–discharge tests, and electrochemical impedance spectroscopy. An important increase in specific capacitances is observed at 0.2 A g−1 from 54.8 F g−1 for FTO/PANI 0.8 film to 157.42 F g−1 for FTO/PANI 0.9 and 195.94 F g−1 for FTO/PANI 1.