A review of the surface activation and modification of biochars

Biomass-derived carbon materials are favored for their abundance and sustainability, and ease of preparation and modification. By surface activation and modification they can have a good electrical conductivity, excellent catalytic activity, a remarkable adsorption capacity, and different interfacial physicochemical functionalities. Surface-modified biochars have found wide applications in energy storage, environmental remediation, and catalysis. However, achieving precise and controllable modification of their active sites remains a challenge. Recent advances and future prospects for controlling their surface morphology, defect engineering, and surface coating strategies, with particular attention to their means of fabrication, are reviewed.