Visible-light-driven catalytic activity enhancement of Pd in AuPd nanoparticles for hydrogen evolution from formic acid at room temperature

Abstract

A series of bimetallic AuPd nanoparticles (NPs) supported by graphene oxide (GO) were synthesized using a facile impregnation-reduction method, which were used as catalysts for the hydrogen evolution reaction (HER) from formic acid (HCOOH) under visible light irradiation at 298K. The results showed that the bimetallic catalysts strongly absorbed visible light, and in comparison with the activities of all the catalsyts with various molar ratios of Au/Pd in the dark, their activities were remarkably enhanced under visible light irradiation. Especially, Au1Pd2/GO exhibited the highest activity featuring initial turnover frequency (TOF) value of 954.2h−1 at 298K, which was among the highest values for the reported heterogeneous catalysts. The enhanced photocatalytic activities of bimetallic catalysts could be mainly attributed to the efficient electron transfer from inactive Au species with localized surface plasmon resonance (LSPR) effect to active Pd sites. Support GO in the catalysts could be regarded as the electron collector and transporter and then also contributed to the enhanced catalytic activity. Furthermore, the catalytic activity of Au1Pd2/GO strongly depended on the intensity and wavelength of incident light, indicating that the visible light irradiation indeed played a key role in the enhanced catalytic activity.