Solvent-driven polymorphic control of CdWO4 nanocrystals for photocatalytic performances

Developing new approaches to polymorphic control is significantly important for function and property design of inorganic materials. In this paper, we proposed a novel solvothermal (hydrothermal) approach for polymorphic control of CdWO4 nanocrystals. By tuning the synthetic parameters such as solvent, reaction temperature, and reaction time, both phase structure and crystallite size of CdWO4 nanocrystals were effectively controlled. As a result, two different crystalline phases of CdWO4 in monoclinic and tetragonal structures were successfully obtained. The photocatalytic performances of CdWO4 polymorphs were investigated by both degradation of MO under UV light irradiation and water splitting under visible light, which clearly demonstrates that the monoclinic structured CdWO4 nanocrystals exhibited a catalytic activity higher than that of tetragonal structured counterpart.