Polymeric Carbon Nitride Nanosheets as a Metal‐Free Heterogeneous Catalyst for Highly Efficient Methanolysis of Polycarbonates

Abstract Improper end‐of‐life treatments of C−O‐linked plastics have caused serious environmental crises and resource waste. One effective method to solve this issue is the catalytic alcoholysis of these plastics. Traditional homogeneous catalysts or metal‐based heterogeneous catalysts for alcoholysis have some drawbacks, such as difficulty in complete separation, environmental threats, and economic burden. Thus, finding a green, low‐cost, recyclable, and highly efficient catalyst substitute is critical. Here, we reported that polymeric carbon nitride nanosheets can serve as a metal‐free heterogeneous catalyst for the methanolysis of polycarbonate, polyethylene terephthalate, and polylactic acid. The catalyst exhibits remarkable performance and could be reused at least four times. NH x was found to be the predominant active site of the catalyst by characterization and experiments. These results show promise for the design of metal‐free heterogeneous catalysts to depolymerize C−O‐linked plastics.