New insights into Se/BiVO4 heterostructure for photoelectrochemical water splitting: a combined experimental and DFT study

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Monoclinic clinobisvanite BiVO4 is one of the most promising materials in the field of solar water splitting due to its band gap and suitable VBM position. We have carried out a comprehensive experimental and periodic density functional theory (DFT) simulations of BiVO4 heterojunction with Selenium (Se/BiVO4), to understand the nature of heterojunction. We have also investigated contribution of Se to higher performance by effecting morphology, light absorption and charge transfer properties in heterojunction. Electronic properties simulations of BiVO4 shows that its VBM and CBM are comprised of O 2p and V 3d orbitals, respectively. The Se/BiVO4 heterojunction has boosted the photocurrent density by three fold from 0.7 to 2.2 mAcm-2 at 1.3 V vs. SCE. The electrochemical impedance and Mott-Schottky analysis consequence favorable charge transfer characteristics which account for the higher performance in Se/BiVO4 compared to the BiVO4 and Se. Finally, spectroscopic, photoelectrochemical and DFT evident that Se makes a direct Z-scheme (band alignments) with BiVO4 where the photoexcited electron of BiVO4 recombine with the VB of Se, consequences electron-hole separation at Se and BiVO4, respectively as a result enhanced photocurrent is obtained.The authors would like to thank the National University of Malaysia for the financial support from grants GUP-2016-089. One of us (H.U) acknowledges the NOTUR supercomputing facilities within the project nn4608

Effects of deposition time on of cobalt sulfide thin film electrode formation

Cobalt sulfide counter electrodes (CE) were prepared using the electrodeposition and ionic exchange deposition method on the fluorine doped tin oxide (FTO). Time deposition effect of thin film were analyzed by using a field emission scanning X-ray diffraction (XRD), field emission electron microscope (FESEM), atomic force microscopic (AFM), and profilometry. The electrocatalytic activities of electrode were measured using cyclic voltammetry (CV) analysis. The growth of cobalt sulfide structure was confirmed by XRD. Therefore, the optimum deposition time of cobalt sulfide thin film electrode at 10 min was exhibiting the higher electrocatalytic activity with cathodic current and surface roughness of -3.36 mA.cm-2 and 34 nm, respectively

Review of Polymer, Dye-Sensitized, and Hybrid Solar Cells

The combination of inorganic nanoparticles semiconductor, conjugated polymer, and dye-sensitized in a layer of solar cell is now recognized as potential application in developing flexible, large area, and low cost photovoltaic devices. Several conjugated low bandgap polymers, dyes, and underlayer materials based on the previous studies are quoted in this paper, which can provide guidelines in designing low cost photovoltaic solar cells. All of these materials are designed to help harvest more sunlight in a wider range of the solar spectrum besides enhancing the rate of charge transfer in a device structure. This review focuses on developing solid-state dye-synthesized, polymer, and hybrid solar cells