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

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/NTO composite 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/NTO composite. Photocatalytic tests demonstrated as-prepared CWS/NTO catalysts exhibited outstanding and stable photocatalytic performances for H-2 production and pollutants degradation under visible light (lambda > 420 nm) irradiation. Specially, 0.50 CWS/NTO sample displayed the highest H-2-evolution activity of 810 lmol.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 capturing experiments confirmed that.O-2(-) and h(+) were primary active species for TC/RhB degradation. Eventually, the probable catalytic mechanism was put forward and detailly analysed. The present work provides perspectives of rational design on NiTiO3-based catalysts with superior photocatalytic performance for energy regeneration and environmental remediation. (C) 2022 Published by Elsevier Inc.

Automated summary

This study successfully synthesized a Cu2WS4/NiTiO3 composite through specific preparation methods, showing excellent photocatalytic performance in terms of H2 production activity and pollutants degradation rates. The results indicated that the 0.50 CWS/NTO sample performed the best, with the highest hydrogen production activity and optimal photodegradation properties.