Inter-embedded Au-Cu₂O heterostructure for the enhanced hydrogen production from water splitting under the visible light

Constructing the heterostructure with noble metals on semiconductors is recognized as a prospective approach to enhance hydrogen generation. In this study, Au-Cu₂O heterostructure particles (HPs) with unique inter-embedded heterostructures were controllably fabricated by a universal reaction between Cu particles and HAuCl₄ solution. Besides, the boosted catalytic performance from the plasmon effects, Au-Cu₂O inter-embedded heterostructure exhibits additional structural advantages to promote the photocatalytic property of hydrogen generation overall water splitting. Under the visible light, the H₂ evolution rate of the Au-Cu₂O HPs is 152 and 22 times higher than that of pure Cu₂O and traditional Cu₂O@Au HPs with Au anchored on the surface of Cu₂O, respectively. On one hand, inter-embedded heterostructure brings more contact areas as the active sites to carry out the direct electron transfer and electromagnetic transfer for the reduction. On the other hand, the finite difference time domain (FDTD) simulations indicate that enhanced electromagnetic fields of Au-Cu₂O HPs form a netlike structure to maximumly accelerate the transfer of hot electrons and separate the electron–hole pairs. Under the joint action of the two, the inter-embed heterostructure exhibits superior photocatalytic property, demonstrating that this study could instruct the design of other metal–semiconductor photocatalysts.