ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Zhiqing Cui,Weikang Wang,Cuijiao Zhao,Chun Chen,Miaomiao Han,Guozhong Wang,Yunxia Zhang,Haimin Zhang,Huijun Zhao
We present the self-assembly synthesis of core–shell structure Au/CeO2 composites with different Au loadings through a spontaneous chemical redox approach at an ambient temperature utilizing HAuCl4 and Ce(NO3)3 as reaction substrates in an alkaline environment. The results demonstrate that the as-synthesized Au/CeO2 composites exhibit spherical shape morphologies with porous structures, composed of Au nanoparticle (∼10 nm) cores and CeO2 nanoparticle shells with abundant oxygen vacancies. The introduction of Au nanoparticles in CeO2 not only effectively improves the visible light utilization efficiency but also provides rich surface catalytic active sites for highly efficient visible light photocatalysis. As visible light photocatalysts (λ > 400 nm), the as-synthesized Au/CeO2 composites with the Au loading amount ≥4.0 wt % exhibit high conversion and selectivity (∼100%) of benzyl alcohol to benzaldehyde under the given experimental conditions. Moreover, Au/CeO2 also shows a general applicability as a visible light photocatalyst for the selective oxidation of other alcohols to corresponding aldehydes or ketones. The photocatalytic mechanism studies indicate that the photoelectrons/holes produced from the photoexcited Au and the formed superoxide radicals in the oxygen vacancies of CeO2 synergistically contribute to the high performance of the selective photocatalytic oxidation of alcohols to aldehydes or ketones.
研究领域:
材料科学
·
光化学
·
催化科学
✓ 已验证
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2016
·
IF 3.698
Guoqiang Gan,Juan Liu,Zhixi Zhu,Ziran Yang,Conglu Zhang,Xiaohong Hou
In this work, magnetic nanoparticles (MNPs) Fe 3 O 4 /CeO 2 were firstly synthesized using three different preparation methods, including coprecipitation, impregnation oxidation-precipitation and impregnation reduction-precipitation, respectively. The catalytic activities of Fe 3 O 4 /CeO 2 MNPs, prepared by above three methods, were compared systematically in terms of the degradation of orange G (OG). The impregnation oxidation-precipitation process was economical and maneuverable due to the usage of air, no need of nitrogen protection and higher utilization efficiency of iron. Response surface methodology based on central composite design were used to investigate the individual and interactive effects of three process parameters on the OG degradation, i.e. the initial pH of the solution, the dosage of H 2 O 2 and the initial concentration of OG. Under the optimal conditions of pH 2.5, H 2 O 2 30 mM, OG 50 mg L −1 , catalyst 2.0 g L −1 and 35 °C, the degradation percentage of OG was 98.2% within 120 min, which agreed well with the modeling prediction (R 2 = 0.9984, and Adj-R 2 = 0.9969). And the degradation reaction well followed the first-order kinetic with R 2 = 0.9969. The Fe 3 O 4 /CeO 2 -OX MNPs showed high catalytic activity, stability and reusability in the degradation of OG.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POROUS MATERIALS
·
2022
·Vol. 30
·期 3
·889-897
·
IF 2.523
Hu Lihua,Chen Li,Mo Xiaohong,Peng Xiong,Xu Wei,Liu Feng,Yan Zongcheng
For the effective utilization of carbon resources, a facile and recyclable heterogeneous catalyst system with high reactivity and stability is urgently needed for chemical fixation of CO 2 . Herein, a micro/nanostructured ZIF-8/CeO 2 composite was designed by direct surface-nucleated ZIF-8 nanoparticles on spindle-like CeO 2 . The ZIF-8 nanoparticles content of the ZIF-8/CeO 2 composite could be tuned by the changing of reaction parameters, such as the molar ratio of reactants and the reaction time. The ZIF-8/CeO 2 composite exhibits remarkably enhanced catalytic activity and superior reusability for cycloaddition reaction of CO 2 and epoxide than its pure substance. The enhanced performance of ZIF-8/CeO 2 composite should be attributed to its high specific surface area and abundant porosity, outstanding thermal stability, and the appearance of a new moderate acid/base site in composite material. Considering the convenient preparation, enhanced catalytic activity and excellent reusability of ZIF-8/CeO 2 composite, this work offers a new strategy to replace ZIFs-based porous catalysts for chemical fixation of CO 2 .
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 8
·1-9
·
IF 5.479
Xie Yu,Tu Xiaolong,Ma Xue,Fang Qingwen,Liu Guangbin,Dai Runying,Qu Fengli,Yu Yongfang,Lu Limin,Huang Xigen
An enzyme-free electrochemical method is described for the determination of trace levels of malathion. It is based on a nanostructured copper-cerium oxide (CuO-CeO 2 ) composite prepared by calcination of a Cu(II)/Ce(III) metal-organic framework. The morphology, crystal structure and elemental composition of composite was studied by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The principle for malathion determination is based on the fact that the redox signal of CuO (best measured at around −0.1 V vs. SCE) (at 100 mV/s) is inhibited by malathion due to affinity between CuO and the sulfur groups of malathion. The introduction of CeO 2 into the composite system further improves the analytical performance. This is attributed to the unique microstructure and the synergistic effect between CuO and CeO 2 . Experimental parameters like solution pH value, Cu/Ce molar ratio, accumulation potential, accumulation time, and CuO-CeO 2 volume on the electrode were optimized. The assay has a linear range of 10 fM to 100 nM and a 3.3 fM detection limit (at S/N = 3). The electrode is selectively inhibited by malathion even in the presence of potentially interfering substances.
A sensitive and effective enzyme-free electrochemical sensor has been developed for the detection of malathion based on CuO-CeO 2 composite derived from bimetallic metal-organic frameworks.
研究领域:
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2024
·
IF 6.7
Changming Zhang,Yuan Wang,Xiaochao Zhang,Zhiyan Dong,Wensheng Wu,Caimei Fan
It is rather essential to increase CO 2 adsorption and improve separation efficiency of photoinduced carriers by solar-driven CO 2 reduction. Herein, we proposed a facile approach to synthesize millimeter-sized polyacrylonitrile-based carbon spheres (PANACSs) as a bifunctional adsorbent and self-nitrogen-doped source under a mild condition, and then embeds the highly active CeO 2 to construct a CeO 2 @PANACSs composite with strong adsorption capacity and high reduction activity. The involved XRD, XPS, SEM, N 2 adsorption/desorption, CO 2 adsorption, UV–vis DRS, EIS, PL and In situ FTIR spectra were characterized. Results suggested that the obtained PANACSs can act as a catalyst to drive the reduction of CO 2 into CO under visible light irradiation. CeO 2 @PANACSs showed the highest performance of photocatalytic reduction of CO 2 for 10 h (210.65 μmol·g −1 ), and the yield of CO evolution is approximately 1.83 times and 17.42 times higher than that of pristine CeO 2 and PANACSs, respectively. We found that the existence of nitrogen-containing functional groups further promoted the adsorption and activation of CO 2 . Among them, pyridinic nitrogen and pyrrolic nitrogen can be used as adsorption and activation sites to accelerate the separation and transfer of e - -h + . Furthermore, Ce 4+ on the surface of CeO 2 acts as an electron capture agent, which captures the electrons that are not transferred in time and reduces itself to Ce 3+ , and then the formed Ce 3+ reduces the adsorbed CO 2 to CO. Finally, the possible mechanism is proposed to depict the photocatalytic CO 2 reduction over the CeO 2 @PANACSs. Our finding provides a noteworthy promising strategy to construct bifunctional composite photocatalysts for achieving the high-efficient CO 2 adsorption and photoreduction to CO.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 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）