Facile synthesis of high quality Z-scheme W18O49 nanowire-g-C3N4 photocatalyst for the enhanced visible light-driven photocatalytic hydrogen evolution

Novel Z-scheme W18O49 nanowire-g-C3N4 nanosheet composite photocatalysts were prepared by a facile solvothermal process. The morphology of W18O49 nanocrystals was significantly changed from urchin sphere to nanowire bundles with the increase of C3N4 quantity. The W18O49-g-C3N4 composites enhance the ability of harvesting visible light, and promote the charge transfer across the composite interface. All the as-prepared composites show higher photocatalytic activity of hydrogen production than that of pure W18O49 and g-C3N4. And the WCN50 composite with 50 mg of g-C3N4 displays the optimal photocatalytic activity with the highest hydrogen production rate of 1.700 mmol g(-1) h(-1) under visible light-irradiation. The improved photocatalytic activity is due to the stronger light harvesting ability, the Z-scheme charge transfer mechanism to promote the interface charge transfer, and the prolonged lifetime of photogenerated electrons. Our work will provide a valuable reference for the design of highly efficient Zscheme photocatalysts for efficiently converting solar energy into chemical fuels. (C) 2018 Elsevier B.V. All rights reserved.