Efficient preparation of P-doped carbon with ultra-high mesoporous ratio from furfural residue for dye removal

Abstract

P-doped mesoporous carbon material is receiving increasing attention in various fields due to its special physicochemical properties, but the research in the field of pollutant removal is rarely reported. Herein, P-doped furfural residue-based carbon materials (PFRC) with ultra-high mesoporous ratio (93.9%), narrow pore size distribution and large surface area (1769.4 m2 g−1) was prepared by a simple method of fast pyrolysis of phosphoric acid treated furfural residue (FR). A series of characterizations were carried out to explore the physicochemical properties and P-doping mechanism of the materials systematically. With the increase of the activation temperature, the evolution of the P-doped structure is as follows: adsorbed phosphate → P-O-Caromatic → O3P-Caromatic → O2P-C2aromatic → OP-C3aromatic. The PFRC500 prepared at 500 °C has the most abundant P-O-Caromatic and P-Caromatic structures, which lead to a higher specific surface area, more developed pore structure and more graphite edge defects than other PFRCs. Methylene blue (MB) adsorption studies showed that PFRC500 had a good adsorption performance with 486 mg g−1 equilibrium adsorption capacity and 97.2% of removal rate (T = 298 K, C0 = 100 mg L−1). The adsorption kinetics and thermodynamics were studied. The role of P structure in MB adsorption was explored for the first time. the adsorption mechanism was explored. The P-O-Caromatic, O3P-Caromatic and O2P-C2aromatic structures are the main chemical adsorption sites, but C3aromatic-PO is not. This work can provide guidance for the design of P-doped mesoporous carbon materials with better adsorption performance in the future.