Synthesis of hierarchical porous carbon with high surface area by chemical activation of(NH_(4))_(2)C_(2)O_(4) modified hydrochar for chlorobenzene adsorption  

作　　者：Jie Wen Zewei Liu Hongxia Xi Bichun Huang 

机构地区：[1]School of Environment and Energy,South China University of Technology,Guangzhou Higher Education Mega Centre,Guangzhou 510006,China [2]School of Chemistry and Chemical Engineering,South China University of Technology,Guangzhou 510640,China [3]The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters,Ministry of Education,South China University of Technology,Guangzhou Higher Education Mega Centre,Guangzhou 510006,China

出　　处：《Journal of Environmental Sciences》2023年第4期123-137,共15页环境科学学报（英文版）

基　　金：supported by the National Key Research and Development Program of China (No.2019YFC1805804)。

摘　　要：In this work,hydrothermal technique combined with KOH activation were employed to develop a series of porous carbons (NPCK-x) using tobacco stem as a low-cost carbon source and (NH_(4))_(2)C_(2)O_(4)as a novel nitrogen-doping agent.Physicochemical properties of NPCK-x were characterized by Brunauer-Emmett-Teller,field emission scanning electron microscopy,X-ray diffraction,Raman microscope,elemental analysis,and X-ray photoelectron spectroscopy.Results showed that the NPCK-x samples possessed large surface areas (maximum:2875 m^(2)/g),hierarchical porous structures,and high degree of disorder.N-containing functional groups decomposed during activation process,which could be the dominant reason for appearance of abundant mesopores and well-developed pore structure.Dynamic chlorobenzene adsorption experiments demonstrated that carbon materials with(NH_(4))_(2)C_(2)O_(4)modification exhibited higher adsorption capacity (maximum:1053 mg/g) than those without modification (maximum:723 mg/g).The reusability studies of chlorobenzene indicated that the desorption efficiency of (NH_(4))_(2)C_(2)O_(4)modified porous carbon reached90.40%after thermal desorption at 100℃ under N2atmosphere.Thomas model fitting results exhibited that the existence of mesopores accelerated the diffusion rate of chlorobenzene in porous carbon.Moreover,Grand Canonical Monte Carlo simulation was conducted to verify that micropores with pore sizes of 1.2–2 nm of the optimized porous carbon were the best adsorption sites for chlorobenzene and mesopores with pore sizes of 2–5 nm were also highly active sites for chlorobenzene adsorption.

关 键 词：Tobacco stem Hierarchical porous carbon N-containing groups Dynamic adsorption CHLOROBENZENE 

分 类 号：X701[环境科学与工程—环境工程] TQ424[化学工程]