RuPd Alloy Nanoparticles Supported on Plasmonic H x MoO 3– y for Efficient Photocatalytic Reduction of p ‐Nitrophenol

p ‐Nitrophenol (PNP) has aroused much concern due to its high toxicity in industrial wastewater and drinking water. Herein, we designed a new plasmonic RuPd/H x MoO 3– y catalyst synthesized by a simple impregnation method, followed by H 2 atmosphere reduction. The synthesized RuPd/H x MoO 3– y hybrid, having RuPd alloy nanoparticles (NPs) anchored on H x MoO 3– y , namely hydrogen‐doped molybdenum oxide support, shows a strong localized surface plasmon resonance (LSPR) absorption peak at around 639 nm. Photocatalytic activity of Ru/H x MoO 3– y hybrid for the reduction of PNP to p ‐aminophenol (PAP) under visible light irradiation can be dramatically improved by alloying with Pd atoms. More importantly, a reasonable mechanism for PNP reduction is proposed. We find that synergetic effect between H x MoO 3– y and RuPd alloy NPs of RuPd/H x MoO 3– y plays a vital role in photocatalytic reduction, in which RuPd alloy NPs act as the active species and plasmonic H x MoO 3– y acts as electron‐donation centre.