Photocatalytic reaction mechanisms at the gas–solid interface for environmental and energy applications

The photocatalytic gas-solid reaction has been regarded as a powerful mean to solve the environmental pollution and energy crisis. However, problems such as catalyst poisoning, low efficiency of reaction, and uncontrollable selectivity are still unsolved restricting the development of photocatalysis. Therefore, it is of significant importance to reveal and elucidate the reaction mechanisms of gas-solid photocatalysis. Herein, five major types of gas-solid photocatalytic reactions including oxidation of NOx, volatile organic compounds (VOCs), NH3 and reduction of CO2, N2 are discussed and summarized. It involves the composition and basic properties of gas molecules, the process of adsorption and activation, and various reaction pathways. Finally, some prospective viewpoints for future development on gas-solid photocatalysis are put forward for further improvements.