Recent progress in rare earth oxides and carbonaceous materials modified ZnO heterogeneous photocatalysts for environmental and energy applications

As a semiconductor photocatalyst, zinc oxide (ZnO) possesses a high oxidative capacity, strong photosensitivity, modest stability, and tunable band structure, which has induced global interest in photocatalytic fuels generation and environmental remediation. However, pristine ZnO suffers from the constraints of visible solar response, swift recombination of excitons and photocorrosion, which significantly lower its photocatalytic performances. On account of unique features, rare earth oxides and carbonaceous materials can be integrated to tune the energy band gap of ZnO to promote the photocatalytic efficiency. This review is focused on rare earth oxides and carbonaceous materials modified ZnO-based composites by highlighting their photocatalytic applications, such as degradation of pollutants, H2 evolution and CO2 reduction. Finally, a summary and future perspectives in this research direction are also provided in this review.