Polarization-enhanced photocatalytic activity in non-centrosymmetric materials based photocatalysis: A review

The conversion of solar energy into chemical energy through semiconductor-based photocatalysis technology is an appealing strategy towards resolving the energy crisis and environmental pollution issues. However, the practical application of photocatalysis is impeded by its limited photocatalytic efficiency due to the intrinsic nature of photocatalysts, i.e., recombination of photogenerated electrons and holes. To this end, non-centrosymmetric (NCS) based photocatalytic materials including piezoelectrics, pyroelectrics, ferroelectrics and nonlinear optical (NLO) materials are attractive, which can not only convert mechanical energy and tem-perature fluctuation in the environment besides solar energy into secondary energy, but can also promote the separation of photogenerated charge carriers due to their built-in electric field resultant polarization, thus greatly improving their photocatalytic performance. Here, we first surveyed the recent advances in of NCS-based pho-tocatalytic materials. Further, the correlation of their polarization-related physical properties with their pho-tocatalytic activities and the strategies towards improving polarization of NCS materials were systematically summarized and highlighted, aiming to clarify the correlation of the improvement of polarization with the enhanced photocatalytic performance. Subsequently, the photocatalytic mechanism and multiple applications of photocatalysis in environmental remediation and energy conversion based on NCS materials were presented. Meanwhile, we discussed the remaining challenges for NCS materials and strategies for enhancing their pho-tocatalytic efficiency. Finally, the development trend and future perspectives of NCS photocatalytic materials in environmental chemical engineering is presented.