RSC Advances
·
2019
·Vol. 9
·期 59
·34658-34670
·
IF 3.049
Xiangyu Wang,Yu Xie,Jun Ma,Ping Ning
The two-stage removal process of tetracycline (TC) in aqueous solutions using a novel photocatalyst based on nano-zero-valent iron (NZVI), g-C3N4 and expanded graphite by carbon layer (EGC) is reported for the first time. The composite (NZVI/g-C3N4@EGC) exhibits remarkable adsorption, reduction ability and visible light activity over the reaction course. Compared with pristine g-C3N4 (25.9%) and pure NZVI (45.9%), NZVI/g-C3N4@EGC achieves high degradation efficiency of TC (98.5%) due to the formation of a heterogeneous photo-Fenton system. This study shows that synergistic effects are achieved in the reaction system, including maintaining the reduction ability of NZVI and enhancing the photocatalytic activity of g-C3N4 by facilitating the separation of photogenerated electrons (e−) and holes (h+). TC removal involved a two-stage process of adsorption–reduction and photo-degradation. The quencher experiments determined that holes (h+) and superoxide radicals (˙O2−) are the major reactive species in the degradation of TC. The degradation pathways of TC were proposed based on the analysis of the intermediates. In addition, NZVI/g-C3N4@EGC revealed a high stability in a five-cycle test and good magnetic properties for facile separation from aqueous solutions. From an application viewpoint, NZVI/g-C3N4@EGC has favorable prospects in the direction of the photocatalytic degradation of antibiotic wastewater.
研究领域:
环境化学
·
材料科学
·
光催化
·
水污染治理
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纳米复合材料
·
抗生素降解
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL RESEARCH
·
2021
·
IF 6.498
Xueqian Yan,Jin Qian,Xiangjun Pei,Lihong Zhou,Rui Ma,Mingkuan Zhang,Yufei Du,Linqin Bai
In this study, a magnetic NiFe 2 O 4 /MWCNTs/BiOI composite were fabricated and applied for enhanced and sustainable photocatalytic degradation of doxycycline (DOX) under UV light irradiation. The as-synthesized material was characterized by a series of techniques and its photocatalytic property was assessed via a couple of batch tests. With the pH at 3.0 and NiFe 2 O 4 /MWCNTs/BiOI loading of 1.5 g L −1 , the DOX degradation (at 45 mg L −1 ) efficiency could achieve 92.18% with the reaction rate constant k of 0.0072 min −1 . The high mineralization of DOX suggests the strong oxidation of both the parent pollutant and the intermediary products in the ternary catalyst system. DRS spectra indicated that compared with BiOI , the introduction of NiFe 2 O 4 and MWCNTs reduces the band gap energy of the NiFe 2 O 4 /MWCNTs/BiOI. The quenching test illustrates that h + , OH and O 2 − all functioned in the developed photocatalytic system, where O 2 − and h + play the dominant roles in DOX degradation. The more efficient electron-h + separation and more oxidizing species induced by UV light resulted in the significant improvement of DOX abatement in the developed coupling system compared with that on either BiOI or NiFe 2 O 4 /MWCNTs. The magnetic property of NiFe 2 O 4 /MWCNTs/BiOI enables its easy separation of the solid catalyst from the reaction solution and the sustainable application in the photocatalysis . Based on the intermediates of DOX decomposition identified by UPLC-MS, the possible degradation routes were proposed accordingly.
研究领域:
环境化学
·
材料科学
·
光催化
·
水污染治理
·
纳米复合材料
·
药物降解
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2019
·Vol. 26
·期 31
·32345-32359
·
IF 2.914
Yu Binglong,Wang Jie,Yang Xiaoxin,Wang Wenlong,Cai Xiulan
In this paper, we synthesized a polyglycerol(PG)-mediated superparamagnetic graphene oxide nanocomposite called MGON, consisting of PG-modified superparamagnetic iron oxide nanoparticles (SPION) covalently bonded to PG-functionalized graphene oxide (GO). MGON exhibits better dispersibility and colloidal stability in aqueous solution than the magnetic graphene oxide reported in the literature. The physicochemical properties of MGON were analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), and UV-vis spectroscopy. Applied to the adsorption of tetracycline (TC) in aqueous solution as an adsorbent, the MGON showed excellent adsorption performance with the maximum adsorption capacity of 684.93 mg/g at 298 K. Adsorption kinetics and isotherm results indicate that the adsorption process conforms to the pseudo-second-order kinetics and Langmuir isotherm models. Adsorption thermodynamics has confirmed that the adsorption process of TC on MGON is spontaneous and endothermic. With the increase of temperature, the adsorption capacity of MGON increases continuously, and the adsorption capacity of MGON is the largest when the pH value is 7. Furthermore, the π-π and cation-π interaction, amidation reaction, and hydrogen bonding can be used to explain the adsorption mechanism of TC on MGON. Desorption and regeneration experiments showed that MGON still had 67.65% regenerative performance after five cycles. Hence, MGON is a promising adsorbent in the removal of tetracycline from wastewater.
研究领域:
环境科学
·
纳米材料学
·
污染物吸附
·
水污染治理
·
环境功能材料
✓ 已验证
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2015
·
IF 3
Yinghao Min,Yanmei Zhou,Min Zhang,Han Qiao,Qi Huang,Tongsen Ma
The removal of ionic liquid (1-butyl-3-methyl imidazolium chloride: BMImCl) was studied from aqueous solution by raw bentonite, acid-activated bentonite and organic-modified bentonite. These types of bentonite sample were characterized by FT-IR, TGA and XRD. The effects of contact time, BMImCl initial concentration, pH, ionic strength, and humic acid on the removal of BMImCl were investigated via batch adsorption experiments. The adsorption kinetics models were applied to predict the adsorption constants, and the kinetic data indicated that the pseudo-second-order model gave a better fit. Furthermore, the Langmuir, Freundlich and Temkin isotherms models were also introduced to describe adsorption process in order to obtain possible mechanism of the removal. The applied isotherms models demonstrated that the adsorption data of acid-activated bentonite samples were well described by Temkin adsorption isotherm, and the isotherm model of organic-modified bentonite was Langmuir adsorption isotherm. The adsorption experiments indicated that these bentonite samples might be applied in repair of soil and water contaminated by ionic liquids.
研究领域:
环境科学
·
土壤修复
·
水污染治理
·
吸附材料
·
环境功能材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）