The Ni2+-LaNiO3/CdS hollow core-shell heterojunction towards enhanced visible light overall water splitting H2 evolution via HER/OER synergism of Ni2+/Ov

The synergetic HER/OER (hydrogen evolution reaction/oxygen evolution reaction) is the crucial issue for overall water splitting. Herein, the Ni2+-LaNiO3/CdS hollow core-shell heterojunction with HER/OER synergism of Ni2+/Ov (oxygen vacancy) is synthesized by a hybrid hydrothermal-reductive-chemical method. As shown, the Ni2+-LaNiO3/CdS (-15480.79 & mu;mol & BULL;g 1 & BULL;h  1) exhibits an obvious visible light photocatalytic enhancement (HER/Photodegradation) than that of single LaNiO3 (-200/-15 folds) and single CdS (-120/-6 folds), and achieves a better overall water splitting performance of -645.23(H2)/321.62(O2) & mu;mol & BULL;g  1 & BULL;h  1 (-110 folds of LaNiO3), and a respectable stability (-5.64% decreasing during 24 h). It mainly ascribes to the synergetic HER/ OER via the Ni2+/Ov, formed heterojunction and hollow core-shell structure. There, the Ni2+ ions can increase solar efficiency and promote photo-generated electron diffusing for HER, the Ov induced by Ni2+ can decrease OER energy barrier and promote hole-related species transportation for OER, the LaNiO3/CdS heterojunction with appropriate potential gradient can improve carrier efficiency, and the hollow core-shell structure can in-crease active sites and solar efficiency. Furthermore, the quickly carrier diffusion can inhibit photocorrosion and hollow spherical structure can increase photocatalytic stability.