scholarly journals Plug and Play Electrodeposition Cell: A Case Study of Bismuth Ferrite Thin Films for Photoelectrochemical Water Splitting

2022 ◽  
Author(s):  
Narayan Firke ◽  
Vaibhavi Gulavani ◽  
Ramchandra Sapkal ◽  
Pankaj Sagdeo ◽  
Ashish Yengantiwar
Keyword(s):  
Water Splitting ◽  
Electrochemical Impedance ◽  
Electronic Band Structure ◽  
Perovskite Phase ◽  
Bismuth Ferrite ◽  
Photocurrent Density ◽  
Visible Absorption ◽  
Electronic Band ◽  
Tauc Plot

Abstract In the present study, we designed and fabricated cost-effective miniaturized versatile electrochemical deposition cell, which is found to be at par performance as compared with conventional electrodeposition techniques. A case study is being undertaken for the electrodeposition of varied thickness of bismuth ferrite (BiFeO3) films on FTO glass substrates. X-ray diffraction (XRD) patterns confirms the structural perovskite phase of BiFeO3 (BFO). UV-Visible absorption spectra and Tauc plot of BFO estimates the direct band gap which lies between 1.9 to 2.1 eV. The properties of bismuth ferrite crystal system such as electronic band structure and density of states (DOS) are investigated theoretically. Photoelectrochemical (PEC) water splitting application is carried out to investigate the best performance of BFO films of varied thickness. The best performer (BFO15) working electrode yields a photocurrent density of ~ 35 µA/cm2 at 0.2 V vs RHE under visible LED (light intensity of 100mW/cm2) in neutral 0.5 M Na2SO4 electrolyte. Incident photon to current conversion (IPCE) measurements, electrochemical impedance spectroscopy (EIS) and Mott-Schottky characteristics confirms the best performance of BFO15 photocathode film.

Application of Titanium Dioxide (TiO2) Based Photocatalytic Nanomaterials in Solar and Hydrogen Energy: A Short Review

2012 ◽  
Vol 712 ◽  
pp. 25-47 ◽  
Author(s):  
Amir Al-Ahmed ◽  
Bello Mukhtar ◽  
Safdar Hossain ◽  
S.M. Javaid Zaidi ◽  
S.U. Rahman
Keyword(s):  
Titanium Dioxide ◽  
Hydrogen Storage ◽  
Water Splitting ◽  
Electronic Band Structure ◽  
Structural Phase ◽  
Research Work ◽  
Size Variation ◽  
Minimum Size ◽  
Hydrogen Energy ◽  
Electronic Band

Tremendous amount of research work is going on Titanium dioxide (TiO2) based materials. These materials have many useful applications in our scientific and daily life and it ranges from photovoltaics to photocatalysis to photo-electrochromics, sensors etc.. All these applications can be divided into two broad categories such as environmental (photocatalysis and sensing) and energy (photovoltaics, water splitting, photo-/electrochromics, and hydrogen storage). Synthesis of TiO2nanoparticles with specific size and structural phase is crucial, for solar sell application. Monodispersed spherical colloids with minimum size variation (5% or less) is essential for the fabrication of photonic crystals. When sensitized with organic dyes or inorganic narrow band gap semiconductors, TiO2can absorb light into the visible light region and convert solar energy into electrical energy for solar cell applications. TiO2nanomaterials also have been widely studied for water splitting and hydrogen production due to their suitable electronic band structure given the redox potential of water. Again nanostructured TiO2has extensively been studied for hydrogen storage with good storage capacity and easy releasing procedure. All these issues and related finding will be discussed in this review.

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 Importance of tailoring lattice strain in halide perovskite crystals

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Hui-Seon Kim ◽  
Nam-Gyu Park
Keyword(s):  
Residual Strain ◽  
Review Paper ◽  
Lattice Mismatch ◽  
Electronic Band Structure ◽  
Perovskite Phase ◽  
Energy State ◽  
Optoelectronic Properties ◽  
Electronic Band ◽  
Halide Perovskite ◽  
The Stability

AbstractIn this review paper, the residual strain of a polycrystalline halide perovskite film is systematically studied based on its structural inhomogeneity, which is closely correlated to the local carrier dynamics caused by a modulated electronic band structure. Long-range collective strain ordering is responsible for the overall structural properties, consequently determining the optoelectronic properties of the perovskite film. Notably, the perovskite phase stability is strongly affected by the internal strain, favoring a lower energy state. The important parameters affecting the residual strain in a real perovskite film, ranging from thermal stress to lattice mismatch and compositional inhomogeneity, are subsequently introduced along with their impacts on the optoelectronic properties and/or the stability of the crystals.

scholarly journals Computational and Experimental Study on Electronic Band Structure of Bismuth Ferrite: A Promising Visible Light Photocatalyst

Ceramist ◽  
2020 ◽  
Vol 23 (4) ◽  
pp. 350-357
Author(s):  
G Thamizharasan ◽  
Eithiraj R.D ◽  
Enhbayar Enhtuwshin ◽  
So Jung Kim ◽  
Niroj Kumar Sahu ◽  
...  
Keyword(s):  
Experimental Study ◽  
Band Structure ◽  
Visible Light ◽  
Electronic Band Structure ◽  
Bismuth Ferrite ◽  
Electronic Band ◽  
Visible Light Photocatalyst

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 Electro-Optical Properties of Monolayer and Bilayer Pentagonal BN: First Principles Study

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 440 ◽  
Author(s):  
Mehran Amiri ◽  
Javad Beheshtian ◽  
Farzaneh Shayeganfar ◽  
Mahdi Faghihnasiri ◽  
Rouzbeh Shahsavari ◽  
...  
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Electronic Band Structure ◽  
Hexagonal Boron Nitride ◽  
Visible Absorption ◽  
Electronic Band ◽  
Metallic Behavior ◽  
Photovoltaic Application ◽  
Spin Polarized ◽  
3D Networks

Two-dimensional hexagonal boron nitride (hBN) is an insulator with polar covalent B-N bonds. Monolayer and bilayer pentagonal BN emerge as an optoelectronic material, which can be used in photo-based devices such as photodetectors and photocatalysis. Herein, we implement spin polarized electron density calculations to extract electronic/optical properties of mono- and bilayer pentagonal BN structures, labeled as B 2 N 4 , B 3 N 3 , and B 4 N 2 . Unlike the insulating hBN, the pentagonal BN exhibits metallic or semiconducting behavior, depending on the detailed pentagonal structures. The origin of the metallicity is attributed to the delocalized boron (B) 2p electrons, which has been verified by electron localized function and electronic band structure as well as density of states. Interestingly, all 3D networks of different bilayer pentagonal BN are dynamically stable unlike 2D structures, whose monolayer B 4 N 2 is unstable. These 3D materials retain their metallic and semiconductor nature. Our findings of the optical properties indicate that pentagonal BN has a visible absorption peak that is suitable for photovoltaic application. Metallic behavior of pentagonal BN has a particular potential for thin-film based devices and nanomaterial engineering.

scholarly journals Role of Nd and Gd Dopants on Multiferroic Behavior of BiFeO-=SUB=-3-=/SUB=- --- A First-Principle Study

2021 ◽  
Vol 63 (10) ◽  
pp. 1552
Author(s):  
R. Mahesh ◽  
P. Venugopal Reddy
Keyword(s):  
Charge Density ◽  
Electronic Band Structure ◽  
Bismuth Ferrite ◽  
Magnetic Moments ◽  
Lone Pair ◽  
Exchange Potential ◽  
Ambient Conditions ◽  
Electronic Band ◽  
Lone Pair Electrons

Electronic band structure, ferroelectric, and magnetic properties of multiferroic Bi1.xRExFeO3 (x=0, 0.16, 0.32, 0.5; RE=Nd and Gd) doped compounds have been investigated using TB-mBJ semi-local (Tran--Blaha modified Becke--Johnson) potential approximation method and WIEN2k code. As spin.orbit coupling (SOC) influences several properties of these materials, SOC corrections were also included in the present study. On the basis of varying band gap values, it has been concluded that the leakage current might have decreased with increasing dopant concentration. It has been concluded from the charge density studies that stereo chemically active 6S2 lone-pair electrons are present at Bi sites and they might be responsible for the displacements of Bi atoms from the centrosymmetric to the non-centrosymmetric structure position leading to the exhibition of ferroelectricity. It was also observed that magnetic moments of iron ions are not integral values probably due to hybridization of Fe electrons with neighboring O ions. To understand ferroelctric properties of these compounds, the real and imaginary parts of the dielectric functions were obtained at ambient conditions and were analyzed using TB-mBJ + SOCpotentials. Finally, it has been concluded that the results obtained in the present investigations may be useful in predicting the properties of bismuth ferrite for possible applications in industry. Keywords: multiferroics, TB-mBJ exchange potential, charge density, spin--orbit coupling (SOC),

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.

The electronic band structure of silicon

Physica ◽  
1954 ◽  
Vol 3 (7-12) ◽  
pp. 967-970
Author(s):  
D JENKINS
Keyword(s):  
Band Structure ◽  
Electronic Band Structure ◽  
Electronic Band
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