JOURNAL OF ENVIRONMENTAL ENGINEERING
·
2024
·Vol. 150
·期 8
·04024038
·
IF 1.6
Jingcheng Wei,Jing Zhang,Bingyan Zhu,Tingfeng Xue,Zejia Song,Sumin Li,Liwei Pan
Activation of peroxymonosulfate (PMS) by catalysts for water treatment is very important for the sulfate radicals-based advanced oxidation technology. Constructing affordable and recyclable transition metal catalysts with high efficiency is highly desirable, but still challenging. In this study, a novel CoAl2O4/Co2O3@γ-Al2O3 catalyst for the activation of PMS was prepared with an excessive impregnation method, and its performance on the catalytic degradation of phenol in water was investigated. The composition and structure of the catalyst were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and N2 adsorption-desorption experiments. It was found that the catalyst could greatly promote the phenol mineralization in water as the total organic carbon removal increased from 4.27% to 57.64% after 60 min of reaction. The presence of Cl− inhibited the catalytic degradation of phenol in water at low concentrations, but promoted the catalytic degradation at high concentrations. However, HCO3− and CO32− revealed inhibitory effects on the catalytic degradation because they could scavenge free radicals in the system. Based on the electron spin resonance technique and the quenching experiments, O12 and SO4−· were identified to be the primary reactive species for the catalytic degradation. The CoAl2O4/Co2O3@γ-Al2O3 could be easily recovered and reused. The toxicity evaluation verified that the toxicity of the treated water was greatly decreased after the catalytic degradation. Therefore, the CoAl2O4/Co2O3@γ-Al2O3 prepared in this study could be an effective catalyst for the catalytic degradation of phenol in water by activating PMS.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Xiaohui Wu,Yulan Jing,Yuanxun Li,Hua Su
The comprehensive properties and sintering temperature of microwave dielectric ceramics are the key factors limiting their practical application. In this work, a novel strategy of complex (Co 1/3 Nb 2/3 ) 4+ ions substituted and adding glass (Li 2 O-B 2 O 3 - SiO 2 -CaO-Al 2 O 3 : LBSCA) was proposed to greatly enhance the microwave dielectric properties of Ba 3 Ti 4- x (Co 1/3 Nb 2/3 ) x Nb 4 O 21 (0 ≤ x ≤ 12 mol%, x CN-BTN) ceramics. A new ceramic of (Co 1/3 Nb 2/3 ) 4+ substitution improved hexagonal phase BTN was successfully fabricated and systematically investigated. As the increased of (Co 1/3 Nb 2/3 ) 4+ ions concentration, the Q× f was greatly increased because of higher packing fraction, and the reduction in the [Nb1/Ti1O 6 ] octahedral distortion caused great changes of τ f . Besides, the P-V-L theory revealed that the Ti/Nb ratio greatly contributed in permittivity ε r , and the Nb-O bonds mainly affected dielectric loss, especially in Nb(1)-O2(1) bond. As a result, the superior microwave dielectric properties were obtained in 6CN-BTN ceramic sintered at 950 °C: ε r ∼40.99 ± 0.48, Q× f ∼17,310 ± 565 GHz, and τ f ∼8.62 ± 4.34 ppm/°C. More encouragingly, 6CN-BTN showed good compatibility with silver, making it a promising K 40 LTCC material for filter and dielectric resonators . This study presented a new strategy to improve the properties of BTN-based materials by complex ions substitution, which was expected to provide a general approach for the design of advanced microwave dielectric ceramics for other material systems.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2023
·
IF 6.1
Lei Wang,Jianjun Li,Mingyan Jin,Xuekai Wang,Liangji Xu,Won-Chun Oh,Changguo Xue,Baojie Yang
In this study, a magnetic CoFe 2 O 4 /Co 2 O 3 /Na-X Zeolite (CFCOZ) composite catalyst was prepared via a co-precipitation hydrothermal method. Comprehensive characterizations suggest that the porous shell layer composed of CoFe 2 O 4 and Co 2 O 3 nanoparticles is evenly supported on Na-X zeolite. The specific surface area of CFCOZ is 266.93 m 2 /g. CFCOZ was exploited to catalyze peroxymonosulfate (PMS) to degrade tetracycline (TC). Catalytic degradation experiments indicated that the TC removal rate in the PMS/CFCOZ system was higher than that in the CoFe 2 O 4 /zeolite/PMS oxidation system. The highest degradation rate reached 96.6 % ([PMS] = 1 mM, 0.2-g/L CFCOZ, [TC] = 20 mg/L, initial pH = 7, room temperature). Several influence factors were investigated, including initial solution pH, PMS concentration, and CFCOZ dosage, etc. on the TC degradation. Electron paramagnetic resonance spectroscopy and reactive species scavenging experiments showed that 1 O 2 , SO 4 − , and O 2 − played the predominant role in the TC removal. The possible catalytic degradation mechanism was proposed. It is found that CoFe 2 O 4 and Co 2 O 3 could synergistically activate PMS, and enhance the circulation efficiency between Co 2+ and Co 3+ to promote the generation of ROS. The cyclic experiments and characterization results between the fresh and the used CFCOZ showed its continuous catalytic activity and good structural stability.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2023
·Vol. 34
·期 2
·1-9
·
IF 2.8
Shen Chang,Zhao Ye,Ji Xinran,Dong Shijun,Zheng Hui,Hu Ji,Zheng Liang
In this work, the electromagnetic of NiCuZn ferrite was enhanced and the sintering temperature was decreased by co-doped Bi 2 O 3 and Co 2 O 3 . The influence of the doping concentration of Co 2 O 3 on the microstructure and magnetic properties of NiCuZn ferrite was studied. Characterizations display that the high density and uniform microstructure of NiCuZn ferrite was obtained at a low sintering temperature of 925 °C. The Co ions were doped in the octahedral B-sites and decreased lattice constant and grain size. The resistivity was also improved after doping appropriate Co ions for the decrease of the Fe 2+ . The saturation magnetization, coercivity, permeability, and cut-off frequency were also enhanced after being doped with the Co 2 O 3 . Consequently, the NiCuZn ferrite doped with 0.30 wt% Bi 2 O 3 and 0.4 wt% Co 2 O 3 possesses a saturation magnetization of ~ 60.014 emu/g, coercivity of ~ 0.033 kA/m, real part of permeability of ~ 269.9 @ 1 MHz, and high cut-off frequency of 8.08 MHz, which can be applied in multi-layer chip inductors.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2026
·
IF 5.6
Jialong Wu,Zhen Li,Weidong Gu,Xinyan Niu,Yunbo Wang,Ding Huang,Shuangshuang Jiang,Manhong Huang,Jun Li,Guanghui Li
Densification of silicon carbide (SiC) ceramic membrane typically requires sintering temperatures above 2000 °C, resulting in high energy consumption and substantial fabrication costs, and conventional SiC membrane exhibit limited removal efficiency for small molecules. To address these challenges, a co-sintering method was employed to fabricate cobaltic oxide (Co 2 O 3 ) loaded SiC catalytic membrane, with the Co 2 O 3 content systematically optimized. Co 2 O 3 functions as both a sintering temperature-lowering aid and an active site for catalytic ozonation of pollutants. Compared to pure SiC membrane (water permeability: 1200 L m −2 h −1 bar −1 ; flexural strength: 10.5 MPa), the Co@SiC membrane demonstrated significant improvements in both water permeability (1400 L m −2 h −1 bar −1 ) and mechanical strength (13.0 MPa). Numerical simulation further elucidated the neck formation dynamics. Moreover, Co@SiC membrane effectively degrades 95 % Congo red within 20 min, attributed to the generation of superoxide radicals (•O 2 − ). Density functional theory (DFT) calculations illustrated Co sites can effectively absorb ozone molecules and break O-O bond in ozone to generate •O 2 − . Fukui index analysis further indicated •O 2 − tend to attack N=N double bonds in dye molecules. This study proposes a comprehensive understanding of low-temperature sintering behavior and catalytic ozonation performance of Co 2 O 3 modified composite membrane, offering a sustainable strategy for membrane fabrication and wastewater treatment.
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2019
·
IF 2.584
Qiuyang Zhang,Caiyun Xu,Hongfeng Yin,Shenghu Zhou
In this work, poly(vinylpyrrolidone)-stabilized 3–5 nm Rh@Co core–shell nanoparticles were synthesized by a sequential reduction method, which was further in situ transformed into Rh-Co2O3 heteroaggregate nanostructures on alumina supports. The studies of XRD, HAADF-STEM images with phase mappings, XPS, TPR, and DRIFT-IR with CO probes confirm that the as-synthesized Rh@Co nanoparticles were core–shell-like structures with Rh cores and Co-rich shells, and Rh-Co2O3 heteroaggregate nanostructures are obtained by calcination of Rh@Co nanoparticles and subsequent selective H2 reduction. The Rh-Co2O3/Al2O3 nanostructures demonstrated enhanced catalytic performance for hydrogenations of various substituted nitroaromatics relative to individual Rh/Al2O3 and illustrated a high catalytic stability during recycling experiments for o-nitrophenol hydrogenation reactions. The catalytic performance enhancement of Rh-Co2O3/Al2O3 nanocatalysts is ascribed to the Rh-Co2O3 interfaces where the Rh-Co2O3 interaction not only prevents the active Rh particles from agglomeration but also promotes the catalytic hydrogenation performance.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Hengtong Zhang,Cailin Liu,Xianyan Ren,Haijun Yang,Shudong Lin
The existed polycarboxylic ether superplasticizer (PCEs) that mainly synthesized in a homogeneous catalytic synthesis has the disadvantages of low conversion rate and poor performance stability. In this paper, high performance PCE-1–5 were synthesized via a heterogeneous H 2 O 2 -ASA (ascorbic acid) redox system catalyzed with MnO 2 , Fe 2 O 3 , Co 2 O 3 , Ni 2 O 3 and ZnO respectively. GPC data show that the molecular weights of PCE-1–5 are higher than that of PCE0 (synthesized via a H 2 O 2 -ASA redox system without transition metal oxides). HPLC indicates that the conversion rates of macromonomer for PCE-1–5 are up to 99.81%, which is 27.47% higher than that of PCE0 (72.34%). As results, PCE-1–5 have a good dispersibility, high water reducing rate and are much benefits to the early hydration of cement paste and the strength of concrete. The mechanism research shows that the cement samples doped with PCE-1–5 have a larger zeta potential , stronger complexing ability with Ca 2+ , and thicker adsorption layer that is as high as 1.03 nm, which makes the spread diameter of cement paste as high as 309 mm. In addition, the obtained microstructure is much denser as is reflected by the nanometer pore size of hardened cement paste (12.26 nm), which makes the 28 d compressive strength of cement test block as high as 60.19 MPa. Generally, the heterogeneous transition metal oxide catalytic redox system provides a good choice for the synthesis of PCEs.
研究领域:
材料科学
·
化学工程
·
水泥与混凝土技术
✓ 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）