Understanding structure-performance correlation of biochar materials in environmental remediation and electrochemical devices

Biochar, a carbon-rich product of biomass pyrolysis under oxygen-limited conditions, has attracted great attention in environment, energy, materials and biology. Systematic summarization of biochar material from the perspective of material design and modulation basically promotes multi-disciplinary development of biochar-based materials in the field of environmental and energy. This paper endows a comprehensive review about the recent advances of biochar material in synthesis, modulation, fundamental understanding and multifunctional performance. Understanding the role of biochar-based adsorbent and electrode in respective field of environmental remediation and electrochemical devices has been correlated. Typically, three kinds of biochar were classified, such as the pure biochar with different morphologies (spherical-, tubular- and nano- biochar), graphitized biochar, chemically functionalized biochar. Meanwhile, the advantages and disadvantages between biochar and other carbon-based materials is contrastively illustrated. It is emphasized that biochar material owns irreplaceable superiority in the widely low-cost raw biomass, the simple and low-energy consumption in manufacture, the porous structure and flexible chemistry adjustment, and the environment friendly and sustainability in natural surroundings. Challenges and perspectives are proposed about how to develop a promising design and manufacture of biochar species for multifunctional applications.