Highly Stable BaZrS3 Chalcogenide Perovskites for Photoelectrochemical Water Oxidation

Chalcogenide perovskites have emerged as potential semiconductor materials for optoelectronic devices due to their superior visible light absorption and high thermal and chemical stability. Here, we report BaZrS₃ chalcogenide perovskites-based photoelectrode for photoelectrochemical water splitting (PEC). Experimental findings reveal that BaZrS₃ exhibits excellent stability in harsh pH conditions (pH 3–13) and shows panchromatic absorption with a band gap of 1.77 eV. Temperature-dependent impedance and Raman spectroscopy unveil the presence of polarons and suggest the possibility of polaron-mediated conduction in this material. Under 1 Sun illumination, the PEC device attains a maximum photocurrent density of 0.36 mA/cm² at 0.323 V vs Ag/AgCl at pH 12 (equivalent to 0 V vs RHE), maintaining stability for 30 min. Notably, the photoanode exhibits remarkable stability before and after the photoelectrochemical reaction. BaZrS₃ photoanode displays high surface charge separation efficiency, promoting the surface oxidation reaction.