Carboxymethyl cellulose stabilized ZnO/biochar nanocomposites: Enhanced adsorption and inhibited photocatalytic degradation of methylene blue
Carboxymethyl cellulose stabilized ZnO/biochar nanocomposites: Enhanced adsorption and inhibited photocatalytic degradation of methylene blue
复制标题
羧甲基纤维素稳定的ZnO/生物炭纳米复合材料：增强吸附并抑制亚甲基蓝的光催化降解
DOI：
10.1016/j.chemosphere.2018.01.022
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发表时间：
2018-04-01
期刊：
影响因子：
8.8
通讯作者：
Wang, Jun
中科院分区：
文献类型：
--
作者：
Wang, Shengsen;Zhou, Yanxia;Wang, Jun
生物炭（BC）负载的纳米氧化锌（nZO）用（nZORc/BC）或不用（nZOR/BC）羧甲基纤维素钠（CMC）包封。X射线衍射和紫外-可见-近红外光谱分析表明，nZOR/BC、nZORc/BC和nZO/BC分别合成了16、10和20 nm的nZO，带隙分别为2.79、3.68和2.62 eV。Langmuir等温线预测nZORc/BC对亚甲基蓝（MB）的饱和吸附量为17.01 g kg（-1），是nZOR/BC和nZO/BC的19倍以上。在紫外光照射下，nZORc/BC、nZO/BC、nZOR/BC和BC对MB的降解率分别为10.9%、61.6%、83.1%和41.6%。清除实验表明羟自由基是CMC降解的主导因素。外源性CMC（2克L-1）增加MB的吸附从10.6%到73.1%，但减少MB的降解从80.7%到41.1%，相对于nZOR/BC。因此，CMC可以通过静电吸引和其他可能的机制增加MB的吸附。MB降解的妥协可能是由于减少了羟基和超氧自由基降解MB的可用性，并增加了ZnO的带隙能量。(C)2018由Elsevier Ltd.出版
Biochar(BC)-supported nanoscaled zinc oxide (nZO) was encapsulated either with (nZORc/BC) or with no (nZOR/BC) sodium carboxymethyl cellulose (CMC). The X-ray diffraction and ultraviolet (UV)-visible-near infrared spectrophotometry revealed that nZO of 16, 10, and 20 nm with energy band gaps of 2.79, 3.68 and 2.62 eV were synthesized for nZOR/BC, nZORc/BC and nZO/BC, respectively. The Langmuir isotherm predicted saturated sorption of methylene blue (MB) was 17.01 g kg(-1) for nZORc/BC, over 19 times greater than nZOR/BC and nZO/BC. Under UV irradiation, 10.9, 61.6, 83.1, and 41.6% of MB were degraded for nZORc/BC, nZO/BC, nZOR/BC and BC. The scavenging experiment revealed hydroxyl radical dominated CMC degradation. Exogenous CMC (2 g L-1) increased MB sorption from 10.6% to 73.1%, but decreased MB degradation from 80.7% to 41.1%, relative to nZOR/BC. Thus, CMC could increase MB sorption by electrostatic attraction and other possible mechanisms. The compromised MB degradation may be ascribed to reduced availability of hydroxyl and superoxide radicals to degrade MB, and increased band gap energy of ZnO. (C) 2018 Published by Elsevier Ltd.