Study on the modification of 3D BiOCl via porous biochar and photocatalytic degradation mechanism

"Waste for waste" is gradually becoming a new requirement for pollution management in the context of "carbon neutrality". Therefore, this study prepared porous biochar (AC) by pyrolyzing plant-derived sugarcane waste and synthesized AC-coated 3D BiOCl composite material (AC-BiOCl) using a one-step solvothermal method. The 3D BiOCl grows in situ, gradually assembling into a flower-like structure, with AC doping into the 3D BiOCl lattice. Experimental results indicate that, compared to 3D BiOCl, AC-BiOCl exhibits outstanding photocatalytic performance under visible light irradiation, as well as excellent stability and reproducibility, with a kinetic constant 3.75 times that of BiOCl. The 3D structure of BiOCl provides numerous active sites, while AC-BiOCl not only shortens the ion diffusion pathway and provides additional active sites, also enhances charge transport efficiency. The strong interaction between AC and 3D BiOCl facilitates carrier separation and inhibits the recombination of photogenerated electron-hole pairs. The effects of catalyst dosage, organic dye concentration, and pH on the photocatalytic performance of AC-BiOCl were investigated. Furthermore, the photocatalytic degradation mechanism was elucidated, revealing that the primary active species in AC-BiOCl are superoxide radicals (•O - 2 ) and holes (h + ). This study proposed a viable strategy for maximizing the utilization of environmentally friendly biomass-modified photocatalytic materials.