Insights into metal/carbon materials activation of persulfate from a structure-property perspective: Performances, tunable reaction pathways and toxicity

Metal/carbon materials have exhibited great potential for engineering applications in environmental remediation as efficient catalysts for persulfate-based advanced oxidation processes (PS-AOPs). The combination of metal and carbon materials integrates the advantages of carbon and metal materials while compensating for their respective shortcomings to achieve higher versatility. However, there is a lack of comprehensive and critical review reporting on the application of metal/carbon materials in PS-AOPs, especially in terms of mechanisms and tunable reaction pathways. In this review, the activation characteristics of different dimensions of metal/carbon materials in their respective systems are summarized and discussed. Attention is focused on establishing structure-property correlations between catalyst active center characteristics and reaction pathways. Notably, in view of the widespread use of these functional engineering materials, the adverse effects of product exposure to the environment can not be ignored. To this end, we conduct a systematic evaluation of aquatic ecotoxic effects of metal/carbon materials for the first time. Meanwhile, the link between material properties and material toxicity is further discussed to guide the design of safe and sustainable metal/carbon catalytic materials. Finally, the problems of existing PS-AOPs technology based on metal/carbon materials are pointed out, and the prospect of their development is given.