WOx/g-C3N4 layered heterostructures with controlled crystallinity towards superior photocatalytic degradation and H2 generation

The construction of g-C3N4 layered heterostructure is crucial to enhance charge carrier separation and expand the photo-adsorption in visible light region. Herein, amorphous and crystalline g-C3N4 nanosheets are produced by adjusting the thermal polycondensation process of precursors. WOx nanobelts are horizontally grown on ultrathin g-C3N4 nanosheets, resulting in the formation of WOx/g-C3N4 layered heterostructures rather than composites. The composition of WOx (WO3, WO2, W18O49) depends strongly on the preparation conditions (e.g. the amount of ascorbic acid). The compositions of WOx and crystallinity of g-C3N4 affect the performance of the heterostructures with the best activity obtained on W18O49/g-C3N4 layered heterostructures. Amorphous W18O49/g-C3N4 layered heterostructures reveal enhanced photocatalytic performance (more than 4 times the performance of g-C3N4), while crystalline W18O49/g-C3N4 layered heterostructure exhibits superior hydrogen generation in visible light region (nearly 7 times higher compared with that of g-C3N4). The results indicate the promising potential of W18O49/g-C3N4 layered heterostructures as superior photocatalysts for degradation and H-2 generation. (C) 2019 Elsevier Ltd. All rights reserved.