Photocatalysis toward Microplastics Conversion: A Critical Review

Microplastics (MPs, particle size < 5 mm) have become increasingly ubiquitous on Earth due to the cleavage and degradation of the heavy use of plastics. MPs have recently been reported to be detected in human blood, alveoli, breast milk, embryos, and other organs, raising concerns about their environmental risks. Photocatalysis has been identified as a potential means for MPs conversion, which utilizes solar energy to stimulate a semiconductor photocatalyst. However, the study of photocatalytic conversion of MPs is still in the incubation period. This review overviews the current state-of-the-art technologies for MPs conversion. Then, the fundamental principles, challenges, analytical techniques, and evaluation indexes of photocatalytic MPs reforming are highlighted. We have systematically summarized the recent advances in the photocatalytic conversion of MPs and identified the key factors influencing photocatalytic performance. Finally, we propose some perspectives for developing efficient photocatalytic systems for reforming MPs. This review will provide a guideline for developing and applying photocatalytic technology for reforming MPs, which will significantly contribute to developing this emerging research field.