Facile in situ fabrication of Cu2O@Cu metal-semiconductor heterostructured nanorods for efficient visible-light driven CO2 reduction

Cuprous oxide (Cu2O) is known to be a promising photocatalyst for CO2 reduction into solar fuels under visible-light irradiation. However, the issues of fast recombination of photogenerated carriers and photocorrosion severely limit its photocatalytic (PC) performance. Herein, we report a unique design of one-dimensional (1D) Cu2O@Cu metal-semiconductor heterostructured nanorods via a simple in situ reduction method for efficient CO2 reduction to hydrocarbons fuels. The well-defined 1D Cu2O nanorod arrays ensure excellent visible-light harvesting capability, and the in situ fabricated Cu2O@Cu heterostructure endows the catalyst with enhanced conductivity as well as highly improved separation and transfer efficiency of photogenerated carriers. Consequently, the optimized Cu2O@Cu heterostructure achieves an apparent quantum efficiency of 2.40% for CH4 and C2H4 and as high as 92% activity retained after four PC cycles. Furthermore, the CO2 reduction performance was further improved when applied a low external bias. This study not only provides a novel, low-cost, and efficient strategy to address the stability and activity issues of Cu2O, but also sheds light on the development of active and robust photocatalysts for energy conversion and storage.