scholarly journals Cobalt Sulfide as Photoelectrode of Photoelectrochemical Hydrogen Generation from Water

2020 ◽  
Vol 49 (12) ◽  
pp. 3063-3069
Author(s):  
Mustafid Amna Rambey ◽  
Khuzaimah Arifin ◽  
Lorna Jeffery Minggu ◽  
Mohammad B. Kassim
Keyword(s):  
Water Splitting ◽  
Hydrogen Generation ◽  
Linear Sweep Voltammetry ◽  
Photocurrent Density ◽  
Cobalt Sulfide ◽  
X Ray Diffraction ◽  
Tauc Plot ◽  
Fourier Transform Raman Spectroscopy ◽  
Different Temperatures ◽  
Pec Water Splitting

This study aimed to synthesize and characterize cobalt sulfide deposited on FTO by hydrothermal method and investigate its photoelectrochemical (PEC) water splitting performance. Cobalt sulfide thin films were produced by annealing at two different temperatures, namely, 400 and 500 °C. X-ray diffraction (XRD) and Fourier transform Raman spectroscopy were used to characterize the phase structure. Scanning electron microscopy was used to observe the morphology. Ultraviolet-visible spectroscopy and linear sweep voltammetry analyses were used to determine the thin-film band gap and evaluate the PEC water splitting performance, respectively. From the XRD and Raman analyses, all the samples produced consisted of mixed phases of Co3S4 and Co9S8. However, each sample contained different percentage phases. The sample annealed at 400 °C contained more Co9S8, whereas that annealed at 500 °C contained comparable amounts of Co3S4 and Co9S8. The morphologies of pre-annealed samples showed vertical flakes with diameters around 200-250 nm and flake thickness around 25-50 nm. When the temperature was increased from pre-annealing temperature to 400 and 500 °C, several flakes were destructed and formed spherical-like clusters. The Tauc plot from absorption analysis showed that the samples annealed at 400 and 500 °C produced similar band gaps at ~2.0 eV. The PEC performance analysis results show that annealing at 400 °C produced the highest photocurrent density of 10 µA/cm2 at a potential of -0.7 V.

scholarly journals Ni/Si-Codoped TiO2 Nanostructure Photoanode for Enhanced Photoelectrochemical Water Splitting

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4102 ◽  
Author(s):  
Ting Li ◽  
Dongyan Ding
Keyword(s):  
Water Splitting ◽  
Annealing Temperature ◽  
Photocurrent Density ◽  
Electrochemical Anodization ◽  
Codoped Tio2 ◽  
Lower Charge ◽  
Si Doped ◽  
Tio2 Nanostructures ◽  
Tio2 Photoanode ◽  
Pec Water Splitting

We synthesized Ni/Si-codoped TiO2 nanostructures for photoelectrochemical (PEC) water splitting, by electrochemical anodization of Ti-1Ni-5Si alloy foils in ethylene glycol/glycerol solutions containing a small amount of water. The effects of annealing temperature on PEC properties of Ni/Si-codoped TiO2 photoanode were investigated. We found that the Ni/Si-codoped TiO2 photoanode annealed at 700 °C had an anatase-rutile mixed phase and exhibited the highest photocurrent density of 1.15 mA/cm2 at 0 V (vs. Ag/AgCl), corresponding to a photoconversion efficiency of 0.70%, which was superior to Ni-doped and Si-doped TiO2. This improvement in PEC water splitting could be attributed to the extended light absorption, faster charge transfer, possibly lower charge recombination, and longer lifetime.

Synthesis and Structure of Titania Nanotubes For Hydrogen Generation

2013 ◽  
Vol 741 ◽  
pp. 84-89 ◽  
Author(s):  
Sangworn Wantawee ◽  
Pacharee Krongkitsiri ◽  
Tippawan Saipin ◽  
Buagun Samran ◽  
Udom Tipparach
Keyword(s):  
Oxalic Acid ◽  
Hydrogen Generation ◽  
Ammonium Fluoride ◽  
Photocurrent Density ◽  
Sodium Sulphate ◽  
Titania Nanotubes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dc Power ◽  
Anodic Voltage

Titania nanotubes (TiO2NTs) working electrodes for hydrogen production by photoelectrocatalytic water splitting were synthesized by means of anodization method. The electrolytes were the mixtures of oxalic acid (H2C2O4), ammonium fluoride (NH4F), and sodium sulphate (VI) (Na2SO4) with different pHs. A constant dc power supply at 20 V was used as anodic voltage. The samples were annealed at 450 °C for 2 hrs. Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD) were used to characterized TiO2NTs microstructure. TiO2NTs with diameter of 100 nm were obtained when pH 3 electrolyte consisting of 0.08 M oxalic acid, 0.5 wt% NH4F, and 1.0 wt% Na2SO4was used. Without external applied potential, the maximum photocurrent density was 2.8 mA/cm2under illumination of 100 mW/cm2. Hydrogen was generated at an overall photoconversion efficiency of 3.4 %.

scholarly journals Combinatorial Search for New Solar Water Splitting Photoanode Materials in the Thin-Film System Fe–Ti–W–O

2020 ◽  
Vol 234 (5) ◽  
pp. 867-885 ◽  
Author(s):  
Swati Kumari ◽  
Chinmay Khare ◽  
Fanxing Xi ◽  
Mona Nowak ◽  
Kirill Sliozberg ◽  
...  
Keyword(s):  
Thin Film ◽  
Water Splitting ◽  
Spin Coating ◽  
Photocurrent Density ◽  
Coated Sample ◽  
X Ray Diffraction ◽  
Film Library ◽  
X Ray ◽  
Solar Water ◽  
Solar Water Splitting

AbstractIn order to identify new solar water splitting photoanodes, Fe–Ti–W–O materials libraries were fabricated by combinatorial reactive co-sputtering and investigated by high-throughput characterization methods to elucidate compositional, thickness, and structural properties. In addition, photoelectrochemical measurements such as potentiodynamic photocurrent determination and open circuit potential measurements were performed using an automated scanning droplet cell. In the thin-film library, a quaternary photoactive region Fe30–49Ti29–55W13–22Ox was identified as a hit composition region, comprising binary and ternary phases. The identified region shows a distinct surface morphology with larger grains (∼200 nm) being embedded into a matrix of smaller grains (∼80–100 nm). A maximum photocurrent density of 117 μA/cm2 at a bias potential of 1.45 V vs. RHE in NaClO4 as an electrolyte under standard solar simulating conditions was recorded. Additional samples with compositions from the hit region were fabricated by reactive co-sputtering and spin coating followed by annealing. Synchrotron X-ray diffraction of sputtered Fe32Ti52W16Ox thin-films, annealed in air (600 °C, 700 °C, 800 °C) revealed the presence of the phases FeTiO3 and Ti0.54W0.46O2. The composition Fe48Ti30W22Ox from the hit region was fabricated by spin coating and subsequent annealing for a detailed investigation of its structure and photoactivity. After annealing the spin-coated sample at 650 °C for 6 h, X-ray diffraction results showed a dominant pattern with narrow diffraction lines belonging to a distorted FeWO4 (ferberite) phase along with broad diffraction lines addressed as Fe2TiO5 and in a small fraction also, Fe1.7Ti0.23O3. In hematite, Fe can be substituted by Ti, therefore we suggest that in the newfound ferberite-type phase, Ti partially substitutes for Fe leading to a small lattice distortion and a doubling of the monoclinic unit cell. In addition, Na from the substrate stabilizes the new phase: its tentative chemical formula is NaxFe0.33Ti0.67W2O8. A maximum photocurrent density of around 0.43 mA/cm2 at 1.45 V vs. RHE in 1M NaOH (pH ∼ 13.6) as an electrolyte was measured. Different aspects of the dependence of annealing and precursor solution concentration on phase transformation and photoactivity are discussed.

A g-C3N4/WO3 photoanode with exceptional ability for photoelectrochemical water splitting

2017 ◽  
Vol 1 (2) ◽  
pp. 338-342 ◽  
Author(s):  
Haibo Li ◽  
Fengyi Zhao ◽  
Jincheng Zhang ◽  
Lei Luo ◽  
Xujing Xiao ◽  
...  
Keyword(s):  
Water Splitting ◽  
Photocurrent Density ◽  
Photoelectrochemical Water Splitting ◽  
Pec Water Splitting

g-C3N4/WO3 heterojunctions with exceptional ability and stability for photoelectrochemical (PEC) water splitting which achieved a high photocurrent density.

Synthesis and Activity of Co-doped Barium Cerium Zirconate for Hydrogen Reforming and Purification

2008 ◽  
Vol 1126 ◽  
Author(s):  
Aravind Suresh ◽  
Joysurya Basu ◽  
Nigel M Sammes ◽  
Barry C Carter ◽  
Benjamin A Wilhite
Keyword(s):  
Hydrogen Generation ◽  
Ac Impedance ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Ac Impedance Spectroscopy ◽  
Methanol Partial Oxidation ◽  
Transmission Electron ◽  
Catalytically Active ◽  
Different Temperatures ◽  
Co Precipitation

AbstractBaCe0.25Zr0.60Co0.15O3-x (BCZC) was synthesized via oxalate co-precipitation route. Material was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Catalytic activity of BCZC with respect to hydrogen generation via methanol partial oxidation was determined. Conductivity of the material at different temperatures and under different environments was determined by AC impedance spectroscopy. XRD and TEM results indicated that BCZC was synthesized as a homogeneous cubic phase material. Catalyst tests indicated that BCZC was catalytically active towards hydrogen generation and AC impedance results were positive enough to warrant further electrochemical studies.

scholarly journals Influence of Au Plasmons and Their Synergistic Effects With ZnO Nanorods for Photoelectrochemical Water Splitting Applications

2021 ◽  
Author(s):  
Sayed Abdul Saboor ◽  
Vidhika Sharma ◽  
Ebrima L. Darboe ◽  
Vidya Doiphode ◽  
Ashvini Punde ◽  
...  
Keyword(s):  
Water Splitting ◽  
Electrochemical Impedance ◽  
Synergistic Effects ◽  
Zno Nanorods ◽  
Visible Region ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
Current Voltage ◽  
Prospective Application ◽  
Pec Water Splitting

Abstract In this paper, Au plasmons and their synergistic effects with ZnO nanorods (ZNs) have been investigated for photoelectrochemical (PEC) water splitting application. Au plasmons and ZNs are deposited electrochemically. Au modified nanostructures have absorption in the visible region as plasmons enhance charge transfer and inhibit charge recombination. ZNs modified with Au (deposition duration ∼ 60 s) has a photo-current density of ∼ 660 µA cm-2, at a bias of 1.0V/SCE. X-ray diffraction and scanning electron microscopy were used to study the structure and surface morphology of fabricated photoanodes. UV-Visible absorption and Photoluminescence spectroscopy were used for optical characterization. We have recorded current-voltage measurements and photo-conversion efficiency measurements to substantiate our observations of the synthesized photoanodes for prospective application in PEC splitting of water. We have also carried out Mott-Schottky, and electrochemical impedance spectroscopy analysis. The analysis reveals that Au modified ZNs based photoanodes are a better proposition than their bare counterparts for PEC water splitting application.

scholarly journals Simple Fabrication of BiVO4 Thin Films Synthesized by Modified SILAR Method: Effect of Film Thickness

2021 ◽  
Author(s):  
chaewon Seong ◽  
Pratik Mane ◽  
Hyojung Bae ◽  
seungwon Lee ◽  
Soon Hyung Kang ◽  
...  
Keyword(s):  
Linear Sweep Voltammetry ◽  
Photocurrent Density ◽  
Thin Layers ◽  
Bandgap Energy ◽  
X Ray Diffraction ◽  
Silar Method ◽  
Layer Adsorption ◽  
Oxide Substrates ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis

Abstract In this study, BiVO4 photoanodes were synthesized using a simple and inexpensive modified successive ionic layer adsorption and reaction (SILAR) method. In particular, the effect of the number of SILAR cycles on the photoelectrochemical (PEC) properties of BiVO4 was evaluated. Scanning electron microscopy analysis revealed the porous surface morphology of the BiVO4 thin layers with irregularly shaped particles formed on the surface of fluorine-doped tin oxide substrates. The crystal structure of BiVO4 was confirmed using X-ray diffraction analysis. The ultraviolet–visible spectrophotometry results indicated that the bandgap energy of the deposited film was approximately 2.4 eV. In addition, the PEC properties of the BiVO4 photoanodes using potentiostat were analyzed. The linear sweep voltammetry curves revealed that the photocurrent density of the BiVO4 samples increased with the increasing number of m-SILAR cycles, and a maximum photocurrent density of approximately 0.83 mA/cm2 was achieved for the BVO-35. These results suggest that an efficient photoelectrode for compact PEC cells can serve as a basis for development.

Sandwich structured WO3 nanoplatelets for highly efficient photoelectrochemical water splitting

2019 ◽  
Vol 7 (45) ◽  
pp. 26077-26088 ◽  
Author(s):  
Guangwei Zheng ◽  
Jinshu Wang ◽  
Guannan Zu ◽  
Haibing Che ◽  
Chen Lai ◽  
...  
Keyword(s):  
Water Splitting ◽  
Photocurrent Density ◽  
Photoelectrochemical Water Splitting ◽  
Highly Efficient ◽  
Pec Water Splitting

Promising PEC water splitting activity with a photocurrent density of 3.16 mA cm−2 at 1.23 V vs. RHE was demonstrated in sandwich structured WO3 with exposed highly reactive (002) facet and superior crystallinity of 2-D nanoplatelets.

Hydrothermal synthesis of Fe2O3/ZnO heterojunction photoanode for photoelectrochemical water splitting

2015 ◽  
Vol 08 (05) ◽  
pp. 1550058 ◽  
Author(s):  
Chao Chen ◽  
Hongye Bai ◽  
Zulin Da ◽  
Meng Li ◽  
Xu Yan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Water Splitting ◽  
Characteristic Curve ◽  
Photocurrent Density ◽  
Zno Film ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron ◽  
Pec Water Splitting

We report a photoanode based on Fe 2 O 3/zinc oxide ( ZnO ) heterojunction synthesized by hydrothermal method for photoelectrochemical (PEC) water splitting. The forming heterojunction is systemically characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results from the I–V characteristic curve and conversation efficiency of Fe 2 O 3/ ZnO heterojunction reveal that the forming heterojunction would be a benefit for electron transferring from conduction band of ZnO to that of Fe 2 O 3. However, the quantity of ZnO film has an effect on the photocurrent density, the suitable of which has shown enhanced PEC performance.

scholarly journals Towards efficient solar-to-hydrogen conversion: Fundamentals and recent progress in copper-based chalcogenide photocathodes

Nanophotonics ◽  
2016 ◽  
Vol 5 (4) ◽  
pp. 524-547 ◽  
Author(s):  
Yubin Chen ◽  
Xiaoyang Feng ◽  
Maochang Liu ◽  
Jinzhan Su ◽  
Shaohua Shen
Keyword(s):  
Water Splitting ◽  
Large Scale ◽  
Carrier Transport ◽  
High Efficiency ◽  
Hydrogen Generation ◽  
Solar Water Splitting ◽  
P Type ◽  
Enormous Number ◽  
High Absorption ◽  
Pec Water Splitting

AbstractPhotoelectrochemical (PEC) water splitting for hydrogen generation has been considered as a promising route to convert and store solar energy into chemical fuels. In terms of its large-scale application, seeking semiconductor photoelectrodes with high efficiency and good stability should be essential. Although an enormous number of materials have been explored for solar water splitting in the last several decades, challenges still remain for the practical application. P-type copper-based chalcogenides, such as Cu(In, Ga)Se2 and Cu2ZnSnS4, have shown impressive performance in photovoltaics due to narrow bandgaps, high absorption coefficients, and good carrier transport properties. The obtained high efficiencies in photovoltaics have promoted the utilization of these materials into the field of PEC water splitting. A comprehensive review on copper-based chalcogenides for solar-to-hydrogen conversion would help advance the research in this expanding area. This review will cover the physicochemical properties of copper-based chalco-genides, developments of various photocathodes, strategies to enhance the PEC activity and stability, introductions of tandem PEC cells, and finally, prospects on their potential for the practical solar-to-hydrogen conversion. We believe this review article can provide some insights of fundamentals and applications of copper-based chalco-genide thin films for PEC water splitting.

Sign in / Sign up

Export Citation Format

Share Document