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

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)_xS_y 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)_xS_y nanoarchitectures. Bi₂S₃–In(OH)_xS_y 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)_xS_y 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)_xS_y 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)_xS_y nanoarchitectures-based photoanodes can be a prospective material for efficient solar-to-hydrogen generation devices.