BaTeS ₃ Chalcogenide Perovskite‐Based Photoanode for Photoelectrochemical Solar Water Oxidation

Chalcogenide perovskites have emerged as a promising candidate for light harvesting applications owing to their high stability, nontoxicity, and exceptional optical and electronic properties. Research on chalcogenide perovskites is widely centered around Zr, Hf, and Ti at the B site of the ABX₃ structure. Here, we report the potential of BaTeS₃ chalcogenide perovskite with Te at the B site for optoelectronic and photoelectrochemical applications. This study comprises a detailed investigation of the material's structural, optical, and electronic properties. The material shows panchromatic light absorption with an indirect bandgap of 2.32 eV. Electrochemical studies reveal that the material is an n-type semiconductor with a band position suitable for water oxidation reactions. The photoanodes fabricated using BaTeS₃ exhibit a photocurrent density of 0.15 mA cm^-2 at 0.62 V versus Ag/AgCl (equivalent to 1.23 V vs. reversible hydrogen electrode).