Fabrication of novel Cu2WS4/NiTiO3 heterostructures for efficient visible-light photocatalytichydrogen evolution and pollutant degradation

A novel type of Cu2WS4/NiTiO3 composite was successfully fabricated via a simple electrospinning/calcination technology and hydrothermal method. The “type-II” electron transport mechanism accounts for the excellent and persistent visible-light catalytic performance for H2 production and pollutants degradation (TC, RhB and Cr(VI)). The influence factors (the pH of solution, dosage of catalyst and concentration of TC) on TC degradation were comprehensively investigated. [Display omitted] •Novel Cu2WS4/NiTiO3 heterostructure was constructed via facile electrospinning/calcination and hydrothermal methods.•The binary composite exhibited excellent and durable visible-light catalytic activities of H2 production and pollutants degradation.•0.50 CWS/NTO sample displayed the highest H2-evolution activity of 810 μmol·g−1·h−1 with the AQE value of 1.65 % at 420 nm.•The effect of operating parameters on TC degradation was investigated.•The reasons accounting for the outstanding performances of these composite were comprehensively investigated. The design and development of efficient and durable catalysts with visible-light response for photocatalytic hydrogen production and pollutants degradation is considered as one of the most challenging tasks. In present work, a novel Cu2WS4/NiTiO3 (abbreviated as × CWS/NTO; x = 0.25, 0.50, 0.75 and 1.00) composite was prepared via a facile electrospinning/calcination technique along with a convenient hydrothermal method. The as-prepared CWS/NTOcomposite was composed of 2D CWS nanosheets and 1D NTO nanofibers manifested by SEM and TEM images. The results of XPS verified the interfacial interaction between CWS and NTO, confirming the heterojunction formation in CWS/NTOcomposite. Photocatalytic tests demonstrated as-prepared CWS/NTO catalysts exhibited outstanding and stable photocatalytic performances for H2 production and pollutants degradation under visible light (λ > 420 nm) irradiation. Specially, 0.50 CWS/NTO sample displayed the highest H2-evolution activity of 810 μmol·g−1·h−1 with the apparent quantum efficiency (AQE) value of 1.65 % at 420 nm. Additionally, it also exhibited the optimal photodegradation properties with the rate constants of 0.030, 0.413 and 0.028 min−1 for TC, RhB and Cr(VI), respectively. The excellent catalytic activities could be attributed to the enhanced visible-light adsorption, high specific surface area and efficient separation of photogenerated charge carriers. The ESR tests and free radicals capt