Multi-element doped biochar composite material and application thereof

The invention discloses a multi-element doped biochar composite material and application thereof, and belongs to the technical field of environmental catalysis and pollutant treatment. The composite material is obtained by co-doping nitrogen, sulfur and cobalt doping elements with polygonatum kingianum residues as a carbon matrix, and a nitrogen and sulfur source is a single-component nitrogen and sulfur source (thiourea). According to the present invention, with the single-component nitrogen-sulfur-source-doped Co-doped polygonatum kingianum herb residue biochar, on one hand, the S element escape can be reduced so as to avoid the poor material repeatability, and on the other hand, the leaching amount of Co during the material catalysis process can be reduced so as to improve the stability of the material catalysis performance; in addition, polygonatum kingianum herb residues are adopted as a carbon source, thiourea is adopted as a nitrogen and sulfur source, N, S and Co are co-doped to form a C-Co3S4-Nx stru