Novel Bismuth Sulfide-Indium (Hydroxy) Sulfide [Bi2S3–In(OH)xSy] nanoarchitecture for efficient photoelectrochemical water splitting

Abstract

In photoelectrochemical (PEC) water splitting, visible light active semiconductors exhibit high conversion efficiency as they are more responsive. Herein, we have realized novel Bi2S3–In(OH)xSy nanoarchitectures for efficient PEC water splitting. We have electrodeposited bismuth vanadate (BiVO4) thin films, and In and S were incorporated via hydrothermal treatment, leading to the formation of novel Bi2S3–In(OH)xSy nanoarchitectures. Bi2S3–In(OH)xSy plane view field emission scanning electron microscope shows a novel patty-packed structure covered with some urchin-like structures, implying a strong surface effect. Electron Impedance spectroscopy (EIS) was employed for impedance measurements. Flat band potential and carrier concentration were determined from Mott-Schottky (MS) plots. The realized novel Bi2S3–In(OH)xSy nanoarchitecture-based photoanodes exhibited a remarkable photocurrent density of 7.77 mA/cm2 at a bias voltage of 1.2 V/RHE under 1.5 AM illumination (1000 W/m2). The heterojunction nanoarchitectures have a reduction in the surface states of the nanocrystal, low lattice misfit, and quick charge transfer, which leads to effective PEC activity. The ABPE for the novel Bi2S3–In(OH)xSy nanoarchitecture-based photoanodes is 4.5% at 0.6 V vs. RHE in an electrolyte solution containing 0.1 M Na2SO4. The results are encouraging and suggest that the Bi2S3–In(OH)xSy nanoarchitectures-based photoanodes can be a prospective material for efficient solar-to-hydrogen generation devices.