Fabrication and characterization of a hierarchical porous carbon from corn straw-derived hydrochar for atrazine removal: efficiency and interface mechanisms

The excellent hierarchical porous carbon was fabricated from corn straw-derived hydrochar by chemical activation using potassium oxalate (K2C2O4). SEM, BET, XPS, XRD, and Raman analysis were carried out for the characterization of the as-obtained samples. The morphology of the as-obtained porous carbon with hierarchical porous structures is made up of a large number of nano-particle aggregates and some nanosheet-like structures, possessing a super-large specific surface area (SSA, up to 2523 m(2) g(-1)) with a large total pore volume of 1.464 cm(3) g(-1). The as-fabricated carbon material rapidly removes atrazine in the first 3 h at the initial concentration of 20 mg L-1 with an adsorption efficiency of 93.6%, which is faster and better than other representative materials reported previously. The acidic conditions are favorable for the atrazine adsorption onto the porous carbon. An efficient adsorbent was fabricated for environmental remediation, and in-depth insights into the interface mechanism between hierarchical porous carbon and atrazine are proposed. In addition, 95% of the adsorption capacity of MPC-1:3 can be recovered by simple annealing treatment.