Boosting nitrogen photofixation through interface electron reconstruction using mixed-valent copper as mediator

Abstract

Solar energy as the inexhaustible and pollution-free renewable energy is widely accepted. Photocatalysis is an efficient green process to store solar energy in the form of chemical energy or utilize it for NH3 production or water treatment reactions. Herein, CeO2–CeCO3OH all-solid-state heterojunctions with Cu2O/Cu Schottky barrier medium are assembled firstly, and the remarkable photo-catalytic performances are obtained. The heterojunction structure can promote the separation efficiencies of photo-induced electron-hole pairs. Otherwise, the as-prepared catalysts also have more visible light absorption capacities and photo-generated oxygen vacancies. In this photocatalytic system, the NH3 yield rate can reach above 597 or 992 μmol·gcal−1·h−1 under the vis-light or full-spectrum lighting without any sacrificial additives, and increase at least 3 times compared to the initial materials. The AQE at 420 nm also reaches more than 0.8 %. Furthermore, the RhB degradation efficiency for the modified sample is approximately 90 %, and the kinetic constant significantly exceeds that of initial sample by 2.7 times. It is the photo-introduced h+ and·O2− species working together to further improve the dye degradation process. This research provides a new insight for the fabrication strategy of photo-catalytic N2 fixation materials.