A broad horizon for sustainable catalytic oxidation of microplastics

Microplastics (MPs) have attracted tremendous attention due to their widespread appearance in the environment and biota, and their adverse effects on organisms. Since plastics are substantially produced to meet human needs, primary and secondary MPs are extensively trapped in wastewater treatment plants, freshwater, drinking water, ocean, air, and soil. The serious MPs pollution calls for efficient treatment strategies Herein, we discuss three catalytic processes (photocatalysis, electrocatalysis, and biocatalysis) for the sustainable management of MPs, and the relevant catalytic mechanisms are clarified. For photocatalysis, three categories (organic, inorganic, hybrid) of photocatalysts are listed, with degradation efficiency of 23%-100%. Next, relative impact factors on photocatalysis, such as characteristics of MPs and photocatalysts, are discussed. Then, some promising electrocatalysts for the degradation/conversion of (micro)plastics and standard electrolyzer designs are briefly introduced. This electrocatalytic method has achieved over 77% of Faradaic efficiency. Next, potential organisms with abundant biocatalysts for degrading different types of MPs are reviewed. Advances in three bioremediation techniques including biositimulation, bioaugmentation, and biosurfactant are outlined. Lastly, perspectives are put forward to promote scientific development in solving environmental issues on MPs pollution in broad fields. This paper provides insights into the development of next-generation techniques for MPs pollution management in a sustainable manner.