Recent progress in biochar-based photocatalysts for environmental remediation

With the accelerating industrialization, environmental pollution has become increasingly severe. Photocatalysis, as a solar-driven advanced oxidation process, has emerged as a promising solution for environmental remediation. Biochar, with its unique surface properties, tunable functional groups, excellent conductivity, and chemical stability, serves as an ideal support for photocatalysts. The integration of photocatalysts with biochar forms biochar-based photocatalysts (Bio-BPs), which synergistically enhance functional groups, porosity, surface active sites, and catalytic performance. This review systematically summarizes the synthesis methods of Bio-BPs to guide optimal preparation strategies, enumerates the advanced characterization techniques, explores modification mechanisms and their effects on photocatalytic activity, examines applications in removing both aqueous pollutants and atmospheric pollutants and discusses sustainable prospects for the future development of Bio-BPs to provide guidelines for designing high-performance biochar-based materials for practical environmental applications.