Construction of Au/CuO/Co₃O₄ Tricomponent Heterojunction Nanotubes for Enhanced Photocatalytic Oxygen Evolution under Visible Light Irradiation

Abstract

Semiconductor-metal heterojunctions are widely used in the design of photocatalyst for water splitting and organic compound degradation. In this work we introduced the design and fabrication of Au/CuO/Co3O4 tricomponent heterojunction to produce oxygen efficiently through photocatalysis of water. A facile and universal strategy was employed to prepare Au/CuO/Co3O4 tricomponent nanotubes. The CuO/Co3O4 nanotubes were first synthesized by electrospinning technique and subsequent thermal treatment. Upon visible light excitation, the CuO/Co3O4 nanotubes in the presence of HAuCl4.4H2O readily transformed into Au/CuO/Co3O4 heterojunction nanotubes. These tricomponent heterostructures demonstrated high O2 generation rate of 2.92 mmol h–1g–1 during the photocatalytic process, a value much larger than that of CuO/Co3O4 nanotube control. The work suggests that the design of tricomponent heterojunctions integrating semiconductor-semiconductor and semiconductor-metal heterojunctions could be an effective route to raise photocatalytic oxygen production efficiency under solar light.