Synthesis of Pd/WO3 and Pt/WO3 composite particles by sonochemical reactions and evaluation of their photocatalytic performance

In this study, precious metal/tungsten trioxide (WO3) composite particles in which palladium (Pd) and platinum (Pt) were loaded on WO3 particles were synthesized via the ultrasonic reduction method. The surface observation of the synthesized composite materials was performed and their photocatalytic performance under visible light irradiation was evaluated from the decomposition rate of methylene blue in aqueous solution. From the TEM image, it was found that the Pd/WO3 composite particles synthesized by the ultrasonic reduction method had a structure in which Pd nanoparticles were supported on WO3 particles. The photocatalytic performance of Pd/WO3 and Pt/WO3 increased with increasing contents of Pd and Pt. When synthesizing Pd(0.5 wt%)/WO3 particles by ultrasonic reduction method, the photocatalytic activity was improved by feeding Pd equivalent to 0.17 wt% per feed three times at regular time intervals, rather than by feeding 0.5 wt% of Pd at a time.