Bimetallic AuPd alloy nanoparticles deposited on MoO3 nanowires for enhanced visible-light driven trichloroethylene degradation

Abstract

Photocatalytic oxidation reactions are regarded as promising green methods for the photodegradation of volatile organic compounds such as trichloroethylene. However, the low efficiency and selectivity of the existing photocatalysts limit practical applications of this technique. In this work, MoO3 nanowires were easily decorated with well-dispersed bimetallic Au–Pd alloyed nanoparticles (AuPd NPs) by a two-step wet-chemical strategy (hydrothermal and chemical reduction). The morphology, size, crystal structures, and mechanism of operation of the photocatalysts were investigated by a series of techniques (X-ray diffraction, scanning and transmission electron microscopy, and photoluminescence spectroscopy, etc.). Deposition of the AuPd NPs on the surface of the MoO3 nanowires led to a dramatic enhancement (11.5 times higher than that of the pure MoO3 nanowires) of the photocatalytic activity of the synthesized photocatalysts. This remarkable improvement of the activity can be attributed to the synergistic effect between Au and Pd NPs, which results in effective separation of the electron and holes and promotes the charge-separation efficiency. The enlarged specific surface area and enhanced stability of the catalysts also resulted in excellent photocatalytic performance. The developed photocatalysts are promising for the removal of volatile organic compounds.