MXene photocatalysts for microplastics degradation under simulated solar illumination

Abstract

Microplastics (MPs) pollution is a widespread and growing problem. Consequently, there is significant interest in photocatalytic degradation and/or conversion of MPs, especially in the case of polyolefins, which are the dominant type of plastic waste and which are difficult to degrade due to their stable C–C backbones. Thus, complete mineralization of polyolefins, as well as their conversion to fuel or other chemicals, is highly challenging and requires the development of novel photocatalyst materials. Here, we investigate an MXene photocatalyst for photocatalytic conversion of polyethylene (PE) plastics in aqueous solutions with and without NaOH. In the absence of NaOH, Ti2CTx MXene results in complete mineralization of pristine PE as well as environmental PE MPs, with CO2 as the dominant reaction product. In contrast, with the addition of 5 M NaOH, hydrogen becomes the dominant product with a high activity exceeding 500 µmol gcat⁻¹.