Tunable Copper-doped BaZrO3 for generation of hydrogen through photocatalytic water splitting

Abstract

BaZrO3, a perovskite-type semiconductor, exhibits exceptional stability and tunable electronic properties, making it a promising candidate for photocatalytic applications. In this study, Cu-doped BaZrO3 was synthesized by a hydrothermal method followed by thermal annealing at 1100 °C. The substitution of Cu within the BaZrO3 lattice improves H2 evolution efficiency. It enhances photosensitivity by introducing electronic defects, increasing the photogenerated electron lifetime (19.89 ns), increasing the specific surface area (19.35 m2/g), and narrowing the band gap (3.4 eV) of calcined BaZrO3 containing 0.5 % Cu. The X-ray Photoelectron Spectroscopy study showed that Cu+/Cu2+ was effectively incorporated into the BaZrO3 structure by substituting for Zr3+/Zr4+, creating O vacancies, and thereby improving the optical performance of the doped materials. The materials exhibit photosensitivity that decreases with the highest Cu doping. However, the most beneficial H2 evolution by photocatalysis occurs at an impurity level is 0.5 % Cu. The importance of the calcination treatment was evident, as it reduces the presence of unwanted species such as BaCO3. Inductively Coupled Plasma studies confirmed a good approximation of the expected Cu concentrations. Photocatalysis results showed the best hydrogen production (27.2 μmol g−1 h−1 and apparent quantum yield = 0.54 %) when BaZrO3 was doped with 0.5 at% copper.