CdS nanoparticles modified Ni@NiO spheres as photocatalyst for oxygen production in water oxidation system and hydrogen production in water reduction system

The exploration of bifunctional catalysts to produce both hydrogen and oxygen will accelerate the progress of overall water-splitting. This paper introduces a facile method to fabricate bifunctional photocatalysts toward the water splitting by doping nano CdS with S vacancies on Ni@NiO nano-spheres. A serious of photocatalytic catalysts were developed and subsequently characterized, the two half-reactions of photocatalytic water splitting were studied in detail by using sacrificial agents, the hydrogen output at 41699 mu mol g(-1) h(-1) (AQE 28.5%, lambda = 420 nm) while the evolution of O-2 is as high as 55120 mu mol g(-1) h(-1) (AQE 35.7%, lambda = 450 nm). It is a strategy that the presence of Ni@NiO can trigger the S vacancy in CdS to act as an effective electron trap, the p-n junction of NiO-CdS, as well as the Schottky barrier between NiO and Ni, can change the dynamic characteristics of photogenerated electrons and prolong their life. These prolonged photogenerated electrons can initiate stable and effective photocatalytic redox reactions.