Biochar-based materials in environmental pollutant elimination, H2 production and CO2 capture applications

Biochar and biochar-based materials have been studied extensively in multidisciplinary areas because of their outstanding physicochemical properties. In this review article, biochar and biochar-based materials in the removal of environmental pollutants, hydrogen generation and carbon dioxide capture were summarized and compared. The interaction mechanisms were discussed from the experimental results and characterization analysis. The high porous structures, active surface sites, (co)doping of single metals/nonmetals, and incorporation of metal oxides or other materials improved the high activity of biochar-based materials in their applications. However, there are still some challenges such as: (1) the fact that H-2 generation with high selectivity or the produced syngas to meet the real application requirement in industrial is the main challenge in H-2 production; (2) the fact that the selective capture of CO2 with high stability, high adsorption capacity and recyclability at low-cost should be considered and focused on; (3) the sorption-(photo)degradation of the organic chemicals; and (4) the fact that the sorption-reduction-extraction/solidification of metals/radionuclides are efficient methods for the elimination of environmental pollutants. In the end, the perspectives, challenges and possible techniques for biochar-based materials' real application in future were described.