Enhanced Activity and Stability of Carbon-Decorated Cuprous Oxide Mesoporous Nanorods for CO2 Reduction in Artificial Photosynthesis

Abstract

The development of photocatalysts with superior activity and stability to produce organic fuels through CO 2 reduction under renewable sunlight is of great significance due to the depletion of fossil fuels and severe environmental problems. In this study, we presented a “hitting three birds with one stone” strategy to synthesize carbon layer coated cuprous oxide (Cu 2 O) mesoporous nanorods on Cu foils via a facile chemical oxidation and subsequent carbonization method. The thin carbon layer not only works as a protective layer to quench the common photocorrosion problem of Cu 2 O but also endows the sample a mesoporous and one-dimensional nanorod structure, which can facilitate reactant molecule adsorption and charge carrier transfer. Substantially, the coated samples exhibited remarkably improved stability as well as decent activity for CO 2 reduction under visible light irradiation. The optimized sample attained an apparent quantum efficiency of 2.07% for CH 4 and C 2 H 4 at λ 0 400 nm, and 93% activity remained after six photoreduction cycles under visible light. This work provides a facile strategy to address the stability and activity issues of Cu 2 O under visible light irradiation, which is presumably suitable for other semiconductors as promising candidates for CO 2 reduction in artificial photosynthesis.