Synergistic promotion of photocatalytic performance by core@shell structured TiO2/Au@rGO ternary photocatalyst

Abstract TiO 2 /Au@rGO(reduced graphene oxide) ternary hybrids were successfully fabricated via a simple two-step method, namely photodepositing of Au nanoparticles (NPs) on large TiO 2 particles first and then coating rGO sheets onto the surface of Au/TiO 2 binary hybrids. The major beneficial structural feature of TiO 2 /Au@rGO hybrids lies in the existence of mutual interfacial area among all of the three components. This outstanding feature enlarges the contact area and improves the separation efficiency of photoexcited charge carriers between components, and thus allowing the efficient realization of fascinating plasmonic effect of Au NPs in photocatalysis. Enabled by this unique structure design, the photocatalytic activity of TiO 2 /Au@rGO hybrids for the degradation of methyl orange was dramatically higher than those of pure TiO 2 , Au/TiO 2 and TiO 2 /@rGO hybrids, under both UV and simulated solar light. The enhancement of photocatalytic activity of TiO 2 /Au@rGO hybrids could be attributed to the synergistic effect between Au NPs, TiO 2 and rGO, and the existence of multi-channel electron transfer paths. This work represents a step toward the rational design of semiconductor-noble metal-graphene hybrids structures for broad-spectrum photocatalysis.