MXene photocatalysts for microplastics degradation under simulated solar illumination

Microplastics pollution is a widespread and growing problem. Consequently, there is significant interest in photocatalytic degradation and/or conversion of microplastics, especially in the case of polyolefins which are 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 development of novel photocatalyst materials. Here we investigate MXene photocatalyst for photocatalytic conversion of polyethylene (PE) plastics in aqueous solutions with and without NaOH. In the absence of NaOH, Ti2CTxMXene results in complete mineralization of pristine PE as well as environmental PE microplastics, with CO2 as a dominant reaction product. In contrast, with the addition of 5M NaOH, hydrogen becomes a dominant product with a high activity exceeding 500 µmol gcat-1.