Perovskite Oxide LaNiO₃ Nanoparticles for Boosting H₂ Evolution over Commercial CdS with Visible Light

LaNiO₃ /CdS heterojunction photocatalysts are constructed by compositing LaNiO₃ nanoparticles with commercially available CdS, and are used for efficient photocatalytic splitting of H₂ O with visible light. The LaNiO₃ /CdS hybrids are characterized systematically using a series of physicochemical techniques. The photocatalytic activity of the perovskite hybrids is examined by H₂ evolution with Na₂ S-NaSO₃ as the hole scavenger. The optimized LaNiO₃ /CdS sample without the assistance of any cocatalyst (e.g., Pt) delivers a high H₂ production rate of 74 μmol h^-1 (e.g., 3700 μmol h^-1  g^-1 ), which is substantially superior to the individual LaNiO₃ and CdS. Besides, the composite photocatalyst also manifests high stability. The greatly improved H₂ production performance of LaNiO₃ /CdS is attributed to the facilitated separation and transport of photoinduced charge carriers, as evidenced by photoelectrochemical (PEC) analyses, such as photoluminscence spectroscopy, transient photocurrent responses, and electrochemical impedance spectroscopy. Moreover, a probable photocatalytic mechanism of the H₂ evolution reaction is proposed on the basis of the results of the catalysis evaluation and PEC tests.