N-doped carbon-coated CoSe2/ZnIn2S4 Z-scheme heterojunction for enhanced visible-light photocatalytic performances

N-doped carbon (NC)/CoSe2/ZnIn2S4 2 /ZnIn 2 S 4 Z-scheme heterojunction was constructed by growing ZnIn2S4 2 S 4 on N-doped carbon-coated CoSe2 2 derived from the metal-organic framework (ZIF-67) via the self-sacrificing template method and hydrothermal method. X-ray photoelectron spectroscopy, electron paramagnetic resonance, and density- functional theory (DFT) calculations demonstrate that NC/CoSe2/ZnIn2S4 2 /ZnIn 2 S 4 (NSZ) Z-scheme heterojunction was constructed with CoSe2 2 as an electron mediator. The optimal 5NSZ composite achieved 97.3% in photocatalytic degradation efficiency of tetracycline hydrochloride (TCH) within 30 min, and H2O2 2 O 2 production of 645.3 mu M under visible light for 60 min. Moreover, the top-flight photocatalytic hydrogen evolution (PHE) rate of 6772.9 mu mol g- 1 h- 1 is 19.1 folds and 2.2 folds higher than pure ZnIn2S4 2 S 4 and Pt-ZnIn2S4, 2 S 4 , respectively. The photoreduction CO2 2 gas produces rates of CO (53.7 mu mol g- 1 h-- 1 ), C2H4 2 H 4 (7.0 mu mol g- 1 h-- 1 ), and C2H6 2 H 6 (6.4 mu mol g- 1 h- 1 ) products were obtained within 10 h under visible light. This work provides an effective strategy for designing unique noble-metal-free Z-scheme heterojunction photocatalysts to purify the environment and produce clean energy.