Au/Cu2O Schottky contact heterostructures with enhanced photocatalytic activity in dye decomposition and photoelectrochemical water splitting under visible light irradiation

Abstract In this work noble metal Au nanoparticles have been successfully deposited on the surface of Cu 2 O microcubes to construct close Au/Cu 2 O Schottky contact heterostructures, in which both an inner electronic field from Au to Cu 2 O and a Schottky barrier are established at the interface of Au and Cu 2 O due to the Schottky junction. Benefiting from this unique structure with synergistic effect of inner electronic field and Schokkty barrier, the as-fabricated Au/Cu 2 O Schottky contact heterostructures exhibit enhanced photocatalytic activity to pure Cu 2 O microcubes in dye decomposition and water splitting under visible light illumination. The photodegradation rate of the as-constructed Au/Cu 2 O Schottky contact heterostructures for methyl orange (MO) is 1.2 times higher than that of pure Cu 2 O microcubes under visible light irradiation for 90 min. The photocurrent density of the as-prepared Au/Cu 2 O heterostructures electrode reaches up to 30 μA cm −2 , which is 3 times higher than that (10 μA cm −2 ) of pure Cu 2 O microcube electrode at 1.23 V vs RHE. The enhanced photocatalytic activity of the as-constructed Au/Cu 2 O Schottky contact heterostructures is attributed to the synergistic effect of inner electronic field and Schokkty barrier. The transfer process of the photoexcited electrons and holes, and the enhancement mechanism of photocatalytic performance of the as-fabricated Au/Cu 2 O heterostructures are discussed in detail. This study opens up new opportunities in designing photoactive materials with highly enhanced performance for solar energy conversion.