Graphene-like carbon sheet-supported nZVI for efficient atrazine oxidation degradation by persulfate activation
Graphene-like carbon sheet-supported nZVI for efficient atrazine oxidation degradation by persulfate activation
复制标题
类石墨烯碳片支撑的 nZVI 通过过硫酸盐活化有效氧化降解莠去津
DOI：
10.1016/j.cej.2020.126309
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发表时间：
2021-01-01
影响因子：
15.1
通讯作者：
Hu, Yang
中科院分区：
文献类型：
--
作者：
Jiang, Qun;Zhang, Ying;Hu, Yang
开发用于负载金属基催化剂的优异载体材料具有挑战性。本文以玉米秸秆和草酸钾（K2 C2 O 4）为原料，采用一锅法制备了类石墨烯碳片（CS）。所得样品具有类似石墨烯的二维层状结构，这提高了生物炭的比表面积。设计了CS负载纳米零价铁（nZVI）复合材料（nZVI@CS），通过过硫酸盐（PS）活化，提高了莠去津的去除率。nZVI@CS-800对阿特拉津的去除效果高于nZVI-PS，说明CS与nZVI之间存在协同效应，促进了阿特拉津的去除。CS由于其大的SSA而有利于nZVI的分散，这可以防止nZVI颗粒的自聚集。同时，降解可以通过优先降解吸附在催化剂上的阿特拉津来促进吸附。SO 4中心点-在阿特拉津的氧化降解过程中起着更为重要的作用。CS可以直接活化PS生成SO 4中心点-，并作为电子穿梭，促进Fe 3+向Fe 2+的转化，提高催化剂的活性。反应60 min后阿特拉津的表观矿化率为38.65%，降解途径包括脱烷基化、烷基氧化和二氯化。高温或低pH值有利于莠去津的氧化降解，而PS或催化剂过量则会抑制莠去津的氧化降解。它可能会受到环境中有机化合物或阴离子的影响。该研究对nZVI@CS原位修复有机污染物的实际应用具有重要意义。
Developing excellent carrier materials for supporting metal-based catalysts is challenging. Herein, a graphene-like carbon sheet (CS) was fabricated from a mixture of corn straw and potassium oxalate (K2C2O4) via a simple one-pot approach. The as-obtained sample possesses a 2D lamellar structure similar to graphene, which improves the specific surface area of the biochar. CS-supported nanoscale zero-valent iron (nZVI) composites (nZVI@CS) were designed to enhance atrazine removal by persulfate (PS) activation. The removal efficiencies of nZVI@CS-800 were higher than that of nZVI-PS, implying that the synergy between CS and nZVI was achieved and promoted the removal efficiency of atrazine. CS facilitates the dispersion of nZVI due to its vast SSA, which could prevent nZVI particles from self-aggregation. Simultaneously, the degradation may be by preferentially degrading the atrazine adsorbed on catalyst to promote adsorption. SO4 center dot- plays a more important role in the oxidative degradation of atrazine. CS can directly activate PS to generate SO4 center dot-, and as an electron shuttle, it can promote the conversion of Fe3+ to Fe2+ and improve the activity of the catalyst. The apparent mineralization rate of atrazine after reaction for 60 min is 38.65%, and degradation pathways include dealkylation, alkyl oxidation and dichlorination. Oxidative degradation of atrazine is favored at high temperature or low pH, while it is inhibited when the amount of PS or catalyst becomes excessive. And it may be impacted by organic compounds or anions in the environment. This study is of great significance for the practical application of nZVI@CS for in situ organic pollution remediation.