RSC Advances
·
2024
·Vol. 14
·期 38
·27789-27798
·
IF 3.9
Zhipeng Xu,Yongliang Qin,Dongdong Wei,Jie Jin,Long Zheng,Jie Xu,Hui Liu,Ranran Chen,Di Wang
The study of the magnetism of tightly arranged nitronyl nitroxide (NN) radicals via Au–S self-assembly is interesting. In this study, a series of radicals (S-NN, D-NN, BS-NN, BD-NN) along with two types of nanomaterials (S-NPs, D-NPs) were synthesized. NN was chosen for the magnetic units. Their structures have been successfully synthesized and analyzed. The spin magnetic properties were characterized by electron paramagnetic resonance (EPR) and superconducting quantum interference device (SQUID) measurement. The analysis revealed that the self-assembled NN formed via Au–S bonds exhibits high packing density. Furthermore, it was gratifying to observe that the AuNPs exhibit ferromagnetism after the surface modification by NN. This results in strong ferromagnetic exchange interactions of S-NPs and D-NPs : JS-NPs = +279.715 K and JD-NPs = +254.913 K, respectively.
研究领域:
材料科学
·
磁学
·
化学合成
✓ 已验证
DOI
PubMed
高影响因子
MACROMOLECULES
·
2017
·
IF 5.835
Jiaxing Zhang,Hongying Shen,Wenguang Song,Guowei Wang
A series of novel linear and hyperbranched copolymers with different topological structures and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) radical distributions were synthesized, and their paramagnetic property was systematically investigated. Based on the ring-opening polymerization (ROP) mechanism of GTEMPO, glycidol (Gly) or ethylene oxide (EO) monomers, the linear Poly(EO-co-GTEMPO) and hyperbranched Poly(Gly-co-GTEMPO) copolymers were obtained from a bifunctional 2,2-dimethyl-1,3-propanediol initiator and a tetrafunctional pentaerythritol initiator, respectively. Alternatively, from the multifunctional macroinitiator of hyperbranched polyglycerol (HPG), the hyperbranched HPG-g-Poly(Gly-co-GTEMPO) and HPG-g-PGTEMPO copolymers were also targeted. The copolymers were characterized by GPC, DSC, and UV–vis analysis. The paramagnetic property of the copolymers was studied and compared by EPR analysis at different concentrations of copolymers and temperatures. The results displayed that the concentrations of copolymers majorly manipulated the signal intensity of EPR spectra, and the temperature majorly modulated the shape of EPR spectra. Essentially, the TEMPO radical distributions in copolymers played an important role: the higher regional density tended to give the EPR spectra with intense, broad peaks, while the lower one led to the regular, well-pronounced EPR spectra. The difference was rationalized to different intramolecular spin–spin exchange and dipole–dipole interaction modulated by the topological structures and the corresponding TEMPO radical distributions.
研究领域:
高分子化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Xiao Zhang,Bin Ren,Xi Li,Biming Liu,Shiwen Wang,Peng Yu,Yanhua Xu,Guoqiang Jiang
Carbon-bridge-modified malonamide (MLD)/g-C 3 N 4 (CN) was prepared by copolymerization of MLD with urea and melamine and loaded with Fe 3 O 4 for the high-efficiency removal of tetracycline (TC) in water under photo-Fenton. The prepared catalysts were characterized by SEM, TEM , N 2 adsorption–desorption analysis, XPS, XRD, and FTIR, which proved that the modification method successfully introduced the C bridge into the carbon nitride molecular system and increased the structural defects of the catalyst. The Carbon-bridge-modified MLD/CN/Fe 3 O 4 also had good visible-light response and charge-separation and transport abilities in the photoelectrochemical test. Degradation results showed that the photo-Fenton degradation of TC reached 95.8%, and the mineralization rate was 55.7% within 80 min at 80 mM H 2 O 2 dosage, 0.5 g/L catalyst dosage, and near-neutral pH by 0.8MLD/CN/Fe 3 O 4 . Moreover, the oxidation products and mineralization pathways of TC were explored by LC-MS. Toxicity analysis indicated low environmental threat of the intermediates in TC mineralization. EPR analysis and H 2 O 2 decomposition efficiency analyses showed an improvement in the H 2 O 2 decomposition performance of 0.8MLD/CN/Fe 3 O 4 . This work could provide a valuable insight for the application of heterogeneous photo-Fenton technology in wastewater treatment .
研究领域:
环境科学
·
化学工程
·
材料科学
·
水处理技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL POLLUTION
·
2020
·
IF 6.793
Mingzhu Hu,Jinyi Zhu,Wenjun Zhou
Oxygen vacancy-enriched N/P co-doped cobalt ferrite (NPCFO) was synthesized using ionic liquid as N and P sources, and then the catalytic performance and mechanism of NPCFO upon peroxymonosulfate (PMS) activation for the degradation of organic pollutants were investigated. The as-synthesized NPCFO-700 exhibited excellent catalytic performance in activating PMS , and the degradation rate constant of 4-chlorophenol (4-CP) increased with the increase of OV concentration in NPCFO-x. EPR analysis confirmed the existence of · OH, SO 4 ·- , and 1 O 2 in the NPCFO-700/PMS system, in which OV could induce the generation of 1 O 2 by PMS adsorption and successive capture, and also served as electronic transfer medium to accelerate the redox cycle of M 2+ /M 3+ (M denotes Co or Fe) for the generation of radical to synergistically degrade organic pollutants. In addition, the contribution of free radical and nonradical to 4-CP degradation was observed to be strongly dependent on solution pH, and SO 4 ·- was the major ROS in 4-CP degradation under acid and alkaline condition, while 1 O 2 was involved in the degradation of 4-CP under neutral condition due its selective oxidation capacity, as evidenced by the fact that such organic pollutants with ionization potential (IP) below 9.0 eV were more easily attacked by 1 O 2 . The present study provided a novel insight into the development of transition metal-based heterogeneous catalyst containing massive OV for high-efficient PMS activation and degradation of organic pollutants.
研究领域:
环境科学
·
催化
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Dahu Ding,Shengjiong Yang,Xiaoyong Qian,Liwei Chen,Tianming Cai
Developing low-cost and efficient metal-free carbon-based catalysts is of great importance but remains a challenge. In this work, rice straw derived biochar was prepared and doped with heteroatoms (N and S) for the catalytic degradation of metolachlor (MET) through activating peroxymonosulfate (PMS). Adsorption process played a critical role for the subsequent degradation process. Surface ketone C (-C = O) was the catalytic active sites for the PMS decomposition. Interestingly, N-doping positively whilst S-doping negatively influenced the MET degradation process. Through experimental investigation and theoretical calculations, N-doping was demonstrated to be beneficial for the interaction between biochar and PMS, thus accelerating the catalytic degradation process. The reactive oxidative species involved in the degradation process were explored by EPR analysis. The degradation pathways were elucidated based on the liquid chromatography time-of-flight mass (LC-TOF-MS) analysis of the degradation products. This study highlights the applications of biochar for the environmental catalysis.
研究领域:
环境科学
·
催化
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）