A facile, green strategy to synthesize N/P self-doped, biomass-derived, hierarchical porous carbon from water hyacinth for efficient VOCs adsorption

Carbon materials prepared using conventional strategies tend to have serious defects such as low porosity and a single pore structure, which compromise their VOC removal performance. Herein we report on a group of experimental porous carbons that were fabricated using water hyacinth (WH) as the starting material which is abundant in of N and P. The experimental results showed that the HWK-H prepared using a co-hydrothermal method exhibited the best performance in adsorbing methylbenzene with a saturated adsorption capacity of 624.7 mg/g. The results of several characterization tests revealed that HWK-H exhibited a high specific surface area (2199.9 m 2 /g), large pore volume (1.415 cm 3 /g), a specific micro/mesoporous structure, surface functional groups (mainly C = O, C-O and COOH), and a very disordered structure. All these properties were the reason for its superb methylbenzene adsorption performance. DFT calculations showed that the presence of N and P groups in the samples improved the energy of adsorption of the porous carbon materials for methylbenzene, thereby promoting its adsorption. GCMC simulation results also revealed that the carbon's micro/mesoporous pores in the range of 0.45–5.0 nm also facilitated the adsorption of methylbenzene. In addition, the multi-component co-adsorption performance and reusability of HWK-H were evaluated and the results showed that HWK-H offered good prospects for industrial application.