Optimized Photoelectrochemical Water Splitting via Orientation-Controlled Growth of 2D In₂S₃ Nanoflakes by Chemical Vapor Desposition

In the present work, vertically aligned ultrathin 2D In2S3 nanosheets are grown with a chemical vapor deposition technique to enhance the photoelectrochemical (PEC) response by increasing the surface area and optical absorption. The 2D vertically aligned In2S3 nanosheets have shown excellent PEC water-splitting performance in terms of an excellent photocurrent density value of 4.5 mA cm–2, an incident photon to the current conversion efficiency of 53%, and hydrogen production of 90% in the visible region, with higher stability over the lateral growth of nanoflakes. Ultrathin vertically aligned In2S3 nanosheets also show high responsivity, high charge carrier density, lower recombination rate, and good space charge layer for excellent water-splitting performance. This straightforward method of creating ultrathin 2D nanosheets of In2S3 has significant potential for other fields where effective absorption and charge separations are required, such as photodetection, optical electronics, and gas sensing.