A novel approach to synthesize the amorphous carbon-coated WO3 with defects and excellent photocatalytic properties

Amorphous carbon-coated tungsten oxide nanocrystals were synthesized via the ultra-rapid solution combustion synthesis method with low-cost, non-toxic starting materials. The amount of glucose played an important role in the synthesis of WO3-x with a suitable amount of carbon. Carbon-coated tungsten oxide existed in the form of round particles with size of similar to 150 nm and the WO3-x nanorods with the length of similar to 20 nm and diameter of 5 nm. After oxidization by H2O2, the WO3-x particles were changed into WO3 with a large amount and variety of defects and kept the original size and nanorod structure. This characteristic resulted in an excellent visible driven photocatalytic performance, and it took about 40 min to degrade the methylene blue (100 mL; 80 mg L-1, MB). Moreover, the material demonstrated good photocatalytic stability under visible light after 5 recyding degradation of MB. The interesting reaction mechanism and the photocatalytic mechanism were studied in this paper. Our study is helpful to design the new photocatalysts, which will have a great application potential in the fields of environmental purification and clean energy. (C) 2016 Elsevier Ltd. All rights reserved.