Surface-engineered biochar: Recent advances in modification strategies for environmental remediation and energy applications

In recent years, biochar has surfaced as an intriguing biosourced substance capable of tackling worldwide issues in energy, agriculture, biomedicine, and environmental sectors. Nonetheless, the effectiveness of biochar relies on the precise adjustment of its surface chemical properties to fulfill specific roles. This review offers an extensive summary of biochar production techniques, highlighting the thermochemical conversion of biomass and the crucial influence of precursor choice and process conditions on biochar characteristics. Furthermore, we investigate sophisticated surface alteration methods, such as chemical activation, physical activation, and functionalization with silane coupling agents, titanates, diazonium salts, and nitrogen-derived compounds. Recent progress in biochar engineering, especially the developments made in the past years, is summarized and linked to their uses in pollutant adsorption, water treatment, catalysis, energy storage, and soil remediation. This review emphasizes the promise of surface-engineered biochar as a sustainable answer to urgent global challenges by exploring the connection between functionalization methods and final uses.