Synthesis of mesoporous p-CuAl2O4/n-YVO4 heterojunction nanocomposites and their utilization as effective photocatalysts for hydrogen evolution

Abstract

The photocatalytic H2 evolution processes have received great attention from the scientific society using semiconductor photocatalysts, and the main bottleneck for the newly synthesized photocatalyst is the swift recombination rate of photoinduced holes and electrons. In this contribution, heterojunction p-CuAl2O4/n-YVO4 photocatalyst was synthesized through the facile sol–gel process utilizing the block copolymer templating. The photocatalytic ability and stability of the p-CuAl2O4/n-YVO4 heterojunction photocatalysts have been examined by H2 evolution in glycerol solution as a hole scavenger under visible illumination. TEM and XRD analyses indicated the formation of YVO4 (5–10 nm) with a tetragonal structure and their uniform interaction with spinel-type CuAl2O4 (5 nm). The CuAl2O4/YVO4 nanocomposites were verified for the first time to be competitive photocatalysts for H2 evolution compared with bare YVO4 NPs. At optimum conditions, the 15 % CuAl2O4/YVO4 nanocomposite revealed an enhanced H2 evolution rate (2994.6 µmolg-1h−1), about 72.5-fold that of bare YVO4 NPs (41.3 µmolg-1h−1). The heterojunction interface of p-CuAl2O4/n-YVO4 NPs was constructed according to their band structures to build S-scheme mechanism. The photoelectrochemical and PL measurements of the CuAl2O4/YVO4 photocatalysts are systematically examined to confirm our photocatalytic H2 evolution studies. It revealed that introducing CuAl2O4 on YVO4 effectively inhibited the recombination of photocarriers, thus promoting the H2 evolution rate. The work provides advantages for plausible designing p-n heterostructures and exhibits new insight to promote photocatalytic performance for potential applications.