Enhancement in photocatalytic H2 evolution utilizing the synergistic effect between dual cocatalysts and heterojunctions

Expediting electrons-holes separation and surface reaction kinetics is deemed to be pivotal factor to determine the photocatalytic performance. Decoration of reductive and oxidative cocatalysts on semiconductors is a resultful approach for motivating electrons-holes separation and surface reaction kinetics. In this work, a ternary 2.4%-(CoSe2@NiS-1)/CdS photocatalyst was developed. Among this compound, reductive cocatalyst CoSe2 not only acted as electron trapping center by extracting photogenerated electrons, but also constructed Schottky junction with CdS to accelerate migration of photogenerated carriers and inhibit the backflow. Meanwhile, oxidative cocatalyst NiS forming p-n type heterojunction with CdS served as hole-trap center to boost transport and consumption of photoinduced holes. Integrating of dual cocatalysts and heterojunctions played synergistic effect in promoting the photocatalytic performance and photo-corrosion stability. 2.4%-(CoSe2@NiS-1)/CdS achieved H2 evolution of 1413.9 μmol and maintained at 85.47% after six cycles. It's expected that this work can provide an insight into designing high active solar energy conversion system.