Advances and challenges of photocatalytic technology for air purification

With the acceleration of the urban industrialization process, air pollutant emission has increased sharply, which seriously endangers the ecological environment and human beings. Solar-driven photocatalysis has the broad-spectrum activity for various inorganic to organic pollutants at ambient temperature without harsh reaction conditions, which shows a very broad application prospect in air purification. However, the photocatalysis technology suffers from the unrevealed reaction mechanism and the deactivation of photocatalysts, which severely limits its practical application. Currently, there is still a huge gap between basic research and industrial application in the field of photocatalytic air purification. This review summarizes recent progress on photocatalytic degradation of air pollutants and categorizes them based on the types of photocatalytic materials and air pollutants, with a focus on photocatalytic reaction mechanisms and the application scenarios of photocatalytic air purification to identify this gap. We also critically discussed the major challenges for promoting applications of photocatalytic technology and put forward the development prospect.