吸附
噻吩
化学吸附
化学
石墨
密度泛函理论
煅烧
核化学
弗伦德利希方程
无机化学
化学工程
有机化学
催化作用
计算化学
工程类
作者
Yuxin Liu,Tianye Wang,Ningning Song,Quanying Wang,Yuqing Wu,Ying Zhang,Hongwen Yu
标识
DOI:10.1016/j.scitotenv.2022.160360
摘要
An efficient, simple, and inexpensive N, S-co-doped hydrochar (SNHC) was synthesized from waste straw by a one-pot hydrothermal process without calcination for the removal of Cr(VI). SNHC demonstrated excellent adsorption performance for Cr(VI) and high stability, achieving a high capacity of 171.33 mg/g (293 K, pH 2) and a capacity retention of 82.73 % after five cycles. The adsorption behavior was determined as a multilayer adsorption process based on chemisorption according to the simulation the results of Freundlich adsorption isotherms and pseudo-second-order models. The characterization of SNHC revealed that graphite N and thiophene S formed by the material were the effective active sites, functioning as electron donors to contribute a significant amount of electrons to reduce Cr(VI) to Cr(III). Therefore, next to electrostatic adsorption and complexation, the synergistic reduction of Cr(VI) by graphite N and thiophene S was the main mechanism for Cr(VI) removal. Additionally, density functional theory calculations indicated a low adsorption energy of thiophene S, which increased the attractive interaction between SNHC and Cr(VI) and played the most important role in reducing Cr(VI). The mechanism of the effect of graphite N and thiophene S on Cr(VI) removal not only offered a comprehensive perspective on the role of N, S co-doped mediation in hydrochar but also provided the basic theory for its practical application.
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