Biochar based catalysts for the abatement of emerging pollutants: A review

Biochar has emerged as a new class of biomass-derived functional materials that can be obtained using a plethora of thermochemical conversion techniques. Biochar-based environmental catalysts have potential applications toward a positive, planet-level impact. Here, recent observations in the activated conversions of emerging contaminants are reviewed, highlighting the most influential advancements, including metal-free processes. The status quo of the underlying interaction mechanisms are summarized, revealing the active functional moieties, persistent free radicals, graphitic degree and electron transfer capacity collectively and synergistically regulate the catalytic potency. These remarkable features convey biochar's high activity and flexibility into viable chemo-redox, photo-, bio-, sono-, and electrocatalysis. Advanced coupling processes and some perspectives on future possibilities are proposed at the end.