scholarly journals Efficient Photoelectrochemical Water Splitting by Tailoring MoS2/CoTe Heterojunction in a Photoelectrochemical Cell

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2341
Author(s):  
Effat Sitara ◽  
Habib Nasir ◽  
Asad Mumtaz ◽  
Muhammad Fahad Ehsan ◽  
Manzar Sohail ◽  
...  
Keyword(s):  
Water Splitting ◽  
Electrochemical Impedance ◽  
Linear Sweep Voltammetry ◽  
Photocurrent Density ◽  
Photoelectrochemical Water Splitting ◽  
Photoelectrochemical Cell ◽  
Electron Hole ◽  
Pair Separation ◽  
Electron Hole Pair ◽  
Electrochemical Impedance Spectroscopic

Solar energy conversion through photoelectrochemical water splitting (PEC) is an upcoming promising technique. MoS2/CoTe heterostructures were successfully prepared and utilized for PEC studies. MoS2 and CoTe were prepared by a hydrothermal method which were then ultrasonicated with wt. % ratios of 1:3, 1:1 and 3:1 to prepare MoS2/CoTe (1:3), MoS2/CoTe (1:1) and MoS2/CoTe (3:1) heterostructure, respectively. The pure materials and heterostructures were characterized by XRD, UV–vis-DRS, SEM, XPS, PL and Raman spectroscopy. Photoelectrochemical measurements were carried out by linear sweep voltammetry and electrochemical impedance spectroscopic measurements. A maximum photocurrent density of 2.791 mA/cm2 was observed for the MoS2/CoTe (1:1) heterojunction which is about 11 times higher than the pristine MoS2. This current density was obtained at an applied bias of 0.62 V vs. Ag/AgCl (1.23 V vs. RHE) under the light intensity of 100 mW/cm2 of AM 1.5G illumination. The enhanced photocurrent density may be attributed to the efficient electron–hole pair separation. The solar to hydrogen conversion efficiency was found to be 0.84% for 1:1 MoS2/CoTe, signifying the efficient formation of the p-n junction. This study offers a novel heterojunction photocatalyst, for PEC water splitting.

scholarly journals Fabrication of a stable light-activated and p/n type AgVO3/V2O5-TiO2 heterojunction for pollutants removal and photoelectrochemical water splitting

2021 ◽  
Author(s):  
Hai Yu ◽  
Zhang Miao ◽  
Yanfen Wang ◽  
Jianguo Lv ◽  
Lei Yang ◽  
...  
Keyword(s):  
Water Splitting ◽  
Photocurrent Density ◽  
Nanorod Arrays ◽  
Electron Hole ◽  
Photodegradation Efficiency ◽  
Conductive Glass ◽  
Electron Hole Pair ◽  
Layer V ◽  
Pollutants Removal ◽  
Efficiency Rate

Abstract In this study, TiO2 nanorod arrays (TiO2) was fabricated and modified with the AgVO3 quantum dots (QDs) decorate on interfacing few-layer V2O5 to form a heterojunction material for removal pollutants and photoelectrochemical (PCE) water splitting. The AgVO3/V2O5-TiO2 nanorod arrays (AgVO3/V2O5-TiO2) synthesized by the secondary hydrothermal method were loaded with conductive glass, which facilitated the formation of one-dimensional (1D) nanorod and p-n junction structures. Through instrumentations, to investigate the structural, morphological, optical, photocatalytic and PCE characteristics of the materials. The TiO2 modified by AgVO3 and V2O5 can significantly improve the visible light optical absorption, the reduce the electron-hole pair binding rate and shorten the band gap (3.07-1.41eV) of TiO2. The resulting photocurrent density (116uA/cm2 ) and photodegradation efficiency (rate constant, k = 0.025min− 1) of AgVO3/V2O5-TiO2 are approximately 20 (6uA/cm2) and 5 times (0.005min− 1) higher than those of bare TiO2, respectively. The AgVO3/V2O5-TiO2 achieved a current density of 10mA at an overpotential of 246.2mV and exhibited excellent oxygen evolution reaction (OER) performance. The systematic PEC experiments concluded that the optimized of the TiO2 interface by AgVO3 and V2O5 could promote the separation and transport of charge carriers.

scholarly journals Direct Observation of Entropy-Driven Electron-Hole Pair Separation at an Organic Semiconductor Interface

2015 ◽  
Vol 114 (24) ◽  
Author(s):  
Nicholas R. Monahan ◽  
Kristopher W. Williams ◽  
Bharat Kumar ◽  
Colin Nuckolls ◽  
X.-Y. Zhu
Keyword(s):  
Direct Observation ◽  
Organic Semiconductor ◽  
Hole Pair ◽  
Electron Hole ◽  
Semiconductor Interface ◽  
Pair Separation ◽  
Electron Hole Pair

Few-Layered MoS2 Nanostructures for Highly Efficient Visible Light Photocatalysis

NANO ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. 1650114 ◽  
Author(s):  
Dan Li ◽  
Jianwei Li ◽  
Caiqin Han ◽  
Xinsheng Zhao ◽  
Haipeng Chu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Electrochemical Impedance ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
Electrochemical Impedance Spectra ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Hole Pair

Few-layered MoS2 nanostructures were successfully synthesized by a simple hydrothermal method without the addition of any catalysts or surfactants. Their morphology, structure and photocatalytic activity were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, electrochemical impedance spectra and UV-Vis absorption spectroscopy, respectively. These results show that the MoS2 nanostructures synthesized at 180[Formula: see text]C exhibit an optimal visible light photocatalytic activity (99%) in the degradation of Rhodamine B owing to the relatively easier adsorption of pollutants, higher visible light absorption and lower electron–hole pair recombination.

scholarly journals Construction of NiMoS3/BC heterostructure photoanodes and optimization of light scattering to improve the photovoltaic performance of dye sensitized solar cells (DSSCs)

2021 ◽  
Author(s):  
T Sumathi ◽  
Sonia A Fredricka ◽  
G Deepa
Keyword(s):  
Solar Cells ◽  
Large Scale ◽  
Photovoltaic Performance ◽  
Dye Sensitized Solar Cells ◽  
Photocurrent Density ◽  
Electron Hole ◽  
Dye Sensitized ◽  
Electron Hole Pair ◽  
Conversion Efficiencies ◽  
Sensitized Solar Cells

Abstract In the last two decades, dye sensitized solar cells (DSSCs) have gotten a lot of attention from researchers and have progressed quickly. To promote commercialization and large-scale application of DSSCs, their efficiency should be increased. This paper details significant advancements in advanced NiMoS3/BC nanocomposites for improving photoanodes and DSSC conversion efficiencies. The fabricated electrode samples were characterized by XRD, SEM, TEM, Raman, UV, PL and BET to explore the structural, morphological and optical properties. A significant reduction band gap with enhanced light absorption and rapid prevention of electron hole pair was explored by UV-DRS and PL studies. The photocurrent density-voltage (J-V) and IPCE characteristics were analyzed for assembled solar cell. The NiMoS3/BC (NMSC5) nanocomposite DSSC showed a PCE of 8.85%, far higher than that of the NiMoS3 (2.45%) and a PCE value equivalent to Pt CE (4.79 %). The enhanced PCE of the proposed electrodes are also discussed in scientifically.

Enhancing the quasi-theoretical photocurrent density of ZnO nanorods via a lukewarm hydrothermal method

Nanoscale ◽  
2020 ◽  
Vol 12 (23) ◽  
pp. 12292-12299
Author(s):  
Ying-Chu Chen ◽  
Zhi-Jie Wu ◽  
Yu-Kuei Hsu
Keyword(s):  
Hydrothermal Method ◽  
Water Splitting ◽  
Light Harvesting ◽  
Zno Nanorods ◽  
Photocurrent Density ◽  
Photoelectrochemical Water Splitting ◽  
Harvesting Efficiency ◽  
Light Harvesting Efficiency

Anti-reflection enhanced the light harvesting efficiency of a ∼10-μm-long 1D ZnO NRA, which is evidently manifested in the quasi-theoretical photocurrent density that reached ∼0.9 mA cm−2 for solar photoelectrochemical water splitting.

scholarly journals Photoactive Tungsten-Oxide Nanomaterials for Water-Splitting

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1871
Author(s):  
Yerkin Shabdan ◽  
Aiymkul Markhabayeva ◽  
Nurlan Bakranov ◽  
Nurxat Nuraje
Keyword(s):  
Tungsten Oxide ◽  
Water Splitting ◽  
Diffusion Length ◽  
Photogenerated Electron ◽  
Photoelectrochemical Cell ◽  
High Electron ◽  
Applied Bias ◽  
Electron Hole ◽  
Research Directions ◽  
Photocatalytic Applications

This review focuses on tungsten oxide (WO3) and its nanocomposites as photoactive nanomaterials for photoelectrochemical cell (PEC) applications since it possesses exceptional properties such as photostability, high electron mobility (~12 cm2 V−1 s−1) and a long hole-diffusion length (~150 nm). Although WO3 has demonstrated oxygen-evolution capability in PEC, further increase of its PEC efficiency is limited by high recombination rate of photogenerated electron/hole carriers and slow charge transfer at the liquid–solid interface. To further increase the PEC efficiency of the WO3 photocatalyst, designing WO3 nanocomposites via surface–interface engineering and doping would be a great strategy to enhance the PEC performance via improving charge separation. This review starts with the basic principle of water-splitting and physical chemistry properties of WO3, that extends to various strategies to produce binary/ternary nanocomposites for PEC, particulate photocatalysts, Z-schemes and tandem-cell applications. The effect of PEC crystalline structure and nanomorphologies on efficiency are included. For both binary and ternary WO3 nanocomposite systems, the PEC performance under different conditions—including synthesis approaches, various electrolytes, morphologies and applied bias—are summarized. At the end of the review, a conclusion and outlook section concluded the WO3 photocatalyst-based system with an overview of WO3 and their nanocomposites for photocatalytic applications and provided the readers with potential research directions.

Photoelectrochemical water splitting with tailored TiO 2 /SrTiO 3 @g-C 3 N 4 heterostructure nanorod in photoelectrochemical cell

2018 ◽  
Vol 85 ◽  
pp. 5-12 ◽  
Author(s):  
Robabeh Bashiri ◽  
Norani Muti Mohamed ◽  
Nur Amirah Suhaimi ◽  
Muhammad Umair Shahid ◽  
Chong Fai Kait ◽  
...  
Keyword(s):  
Water Splitting ◽  
Photoelectrochemical Water Splitting ◽  
Photoelectrochemical Cell

scholarly journals Photocatalytic water splitting by N-TiO2 on MgO (111) with exceptional quantum efficiencies at elevated temperatures

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Yiyang Li ◽  
Yung-Kang Peng ◽  
Liangsheng Hu ◽  
Jianwei Zheng ◽  
Dharmalingam Prabhakaran ◽  
...  
Keyword(s):  
Water Splitting ◽  
Elevated Temperatures ◽  
Practical Method ◽  
Charge Carriers ◽  
Molar Ratio ◽  
Electron Hole ◽  
Photocatalytic Water Splitting ◽  
The Past ◽  
Electron Hole Pair ◽  
Electric Field Polarization

Abstract Photocatalytic water splitting is attracting enormous interest for the storage of solar energy but no practical method has yet been identified. In the past decades, various systems have been developed but most of them suffer from low activities, a narrow range of absorption and poor quantum efficiencies (Q.E.) due to fast recombination of charge carriers. Here we report a dramatic suppression of electron-hole pair recombination on the surface of N-doped TiO2 based nanocatalysts under enhanced concentrations of H+ and OH−, and local electric field polarization of a MgO (111) support during photolysis of water at elevated temperatures. Thus, a broad optical absorption is seen, producing O2 and H2 in a 1:2 molar ratio with a H2 evolution rate of over 11,000 μmol g−1 h−1 without any sacrificial reagents at 270 °C. An exceptional range of Q.E. from 81.8% at 437 nm to 3.2% at 1000 nm is also reported.

Effects of yttrium, ytterbium with tungsten co-doping on the light absorption and charge transport properties of bismuth vanadate photoanodes to achieve superior photoelectrochemical water splitting

2020 ◽  
Vol 4 (3) ◽  
pp. 1496-1506 ◽  
Author(s):  
Umesh Prasad ◽  
Jyoti Prakash ◽  
Arunachala M. Kannan
Keyword(s):  
Charge Transport ◽  
Transport Properties ◽  
Water Splitting ◽  
Light Absorption ◽  
Bismuth Vanadate ◽  
Photoelectrochemical Water Splitting ◽  
Photoelectrochemical Cell ◽  
Co Doping ◽  
Effective Water

Effective water splitting by a photoelectrochemical cell using a BiVO4 photoanode is limited by the light absorption and charge transport properties.

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.

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