The Influence of Annealing on the Sb Layer in the Synthesis of [001]‐Oriented Sb ₂ Se ₃ Film for Photoelectrochemical Hydrogen Gas Generation

Abstract This work reports a new thermal treatment approach to obtain [001]‐oriented Sb 2 Se 3 film, which consists of preliminary annealing of the Sb layer before its selenization. Among the different Sb annealing temperatures assessed, the one at 200 °C followed by selenization (Sb 2 Se 3 (Sb‐A200)) results in a considerably high texture coefficient at the [001] direction, whereas the Sb 2 Se 3 film obtained only by selenization of the non‐annealed Sb film (Sb 2 Se 3 (Sb‐NA)) features preferential orientation at the [ hk 0] direction. In terms of photoelectrochemical (PEC) performance for H 2 generation, the Sb 2 Se 3 (Sb‐A200)/CdS/TiO 2 /Pt film delivers a substantial photocurrent density of −5.65 mA cm −2 at 0 V RHE , which is 10 times higher compared to the Sb 2 Se 3 (Sb‐NA)/CdS/TiO 2 /Pt film. Additionally, the employment of the Sb annealing step results in stable PEC performance of the Sb 2 Se 3 film over 7000 s, meaning that the photocorrosion is minimized. The improved PEC performance of the Sb 2 Se 3 film is attributed to better crystallinity and composition closer to the stoichiometric condition, as well as the preferential orientation at the [001] direction that favors charger carriers' transportation. At last, the findings of this work feature an innovative thermal treatment approach to obtain [001]‐oriented Sb 2 Se 3 film to further improve H 2 generation from PEC water splitting.