Journal of Energy Storage
·
2022
·
IF 8.907
Chengzhen Wei,Zhaojiang Yu,Zhencai Guo,Nan Guan,Wen Xing,Weimin Du,Lin Liu,Yongming Zhang,Cheng Cheng
Yolk-shelled hollow structures with unique structural features are incredibly attractive for energy storage systems . Here we present a self-template strategy to prepare carbon coated yolk-shelled Fe 3 O 4 -CeO 2 hollow spheres. First, yolk-shelled Fe-Ce glycerate precursors are designed by a solvothermal method. Afterward, the carbon coated yolk-shelled Fe 3 O 4 -CeO 2 hollow spheres are eventually synthesized via calcinations the obtained precursors in Ar. Such unique structures endow the Fe 3 O 4 -CeO 2 with abundant inner cavities, large surface area and more electroactive site. As electrode material for supercapacitors , a large capacity of 430 C g −1 is obtained at 2.0 A g −1 , and it can be as high as 198.4 C g −1 even at 20 A g −1 . Moreover, it also takes outstanding rate capability and superior cycling durability (only 5.2 % capacity reduction over 5000 cycles at 6.0 A g −1 ). Furthermore, a quasi-solid-state flexible asymmetric supercapacitor device is constructed by Fe 3 O 4 -CeO 2 cathode and activated carbon anode . The device manifests a high energy density of 46.6 Wh kg −1 at 2.0 A g −1 ( versus 1650 W kg −1 power density). Even at 15 A g −1 , the energy density is still 21 Wh kg −1 with 12,441 W kg −1 . We envision that this work not only explores a promising electrode material for supercapacitors, but also provides an alternative avenue to prepare yolk-shelled hollow structures toward energy storage applications .
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Shuai Wang,Jirong Long,Tian Jiang,Li Shao,Dan Li,Xianchuan Xie,Feigao Xu
Magnetic Fe 3 O 4 /CeO 2 /g-C 3 N 4 (FCG) composites with a visible-light response were successfully synthesized and characterized as a heterogeneous Fenton-like catalyst for tetracycline hydrochloride (TCH) degradation. The optimal mass ratio, pH value, catalyst addition, H 2 O 2 concentration, and temperature were explored. Photodegradation studies showed the best activity when the mass ratio of the composite was 1:0.75:0.75 (F 1 C 0.75 G 0.75 ) and the removal rate of TCH by F 1 C 0.75 G 0.75 reached 96.63% after 180 min. The first order kinetic constant of the reaction system was 0.0533 min −1 . According to the test of free radical scavenger and metal leaching tests, the Fenton-like degradation of TCH by F 1 C 0.75 G 0.75 composite was analyzed. g-C 3 N 4 effectively reduced the leaching of Fe and the location where TCH was attacked by hydroxyl radicals was mainly on the surface of the catalyst. The reusability of the F 1 C 0.75 G 0.75 composites was also studied after five cycles.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
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
Molecular Catalysis
·
2019
·
IF 2.938
Juan Liu,Xia Wu,Jingjing Liu,Conglu Zhang,Qi Hu,Xiaohong Hou
In this work, ofloxacin degradation was investigated by using Fe 3 O 4 -CeO 2 /activated carbon (AC) as heterogeneous Fenton catalyst. Response surface methodology based on central composite design (CCD) was used to investigate individual and interactive effects of three parameters on the ofloxacin degradation, i.e., solution pH, H 2 O 2 dosage and initial ofloxacin concentration. Optimal conditions were determined to be pH 3.3, H 2 O 2 20.0 mM, ofloxacin 12.0 mg L −1 and catalyst 0.5 g·L −1 . The ofloxacin degradation efficiency and the total organic carbon (TOC) removal was 95% and 54% within 60 min, respectively. The obtained results agreed well with the modeling prediction ( R 2 = 0.9826, and Adj- R 2 = 0.9783). The kinetic analysis implied that the reaction followed first-order kinetic with R 2 = 0.9965. According to mass spectrometry qualitative analysis, eight intermediates of ofloxacin were detected and two possible degradation pathways were proposed. The catalyst still showed degradation efficiency of 82.4% toward ofloxacin after five runs.
研究领域:
环境科学
·
化学工程
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Yuxiang Sun,Li Xu,Xin Liu,Yaodong Shen,Yu Zhang,Ning Gu,Fei Xiong
Superoxide anion (O 2 •-), hydrogen peroxide (H 2 O 2 ), hydroxyl radical (•OH) are the main components of endogenous reactive oxygen species (ROS), while •OH shows the most significant cytotoxicity to tumor cells. Thus effective and continuous •OH generation is critical to ROS-based tumor treatment. Herein, we assembled coronal-shaped Fe 3 O 4 @CeO 2 nanoparticles (NPs) to achieve relay conversion of O 2 •- → H 2 O 2 → •OH in acute myeloid leukemia (AML) cells, where CeO 2 NPs function as the mimetic enzyme of superoxide dismutase (SOD) to convert O 2 •- → H 2 O 2 and Fe 3 O 4 NPs act as the peroxidase (POD) mimetic enzyme to realize H 2 O 2 → •OH. We found that assembled Fe 3 O 4 @CeO 2 got an enhanced POD activity and SOD activity due to the mechanism of more efficient relay conversion at sub-nanometer distance. As a result, assembled Fe 3 O 4 @CeO 2 successfully promoted the relay conversion of O 2 •- → H 2 O 2 → •OH in vitro and in AML cells, causing a continuous generation of •OH by utilizing the oxygen source of endogenous O 2 •- and endogenous H 2 O 2 . In AML cells, reportedly, O 2 •- and H 2 O 2 were both in high levels and the generation of O 2 •- is sustainable. Furthermore, Fe 3 O 4 @CeO 2 -driven the endogenous ROS axial conversion exacerbated AML cells apoptosis and prolonged the survival time of systemic AML mice, showing the worth of this relay conversion mechanism. Therefore, assembled Fe 3 O 4 @CeO 2 provides an ideal tool for the directed conversion of intracellular ROS and continuous generation of •OH. Importantly, the targeted conversion of ROS by assembling multi-enzyme system is an effective strategy for the intervention of ROS.
研究领域:
纳米技术
·
癌症生物学
·
生物化学
·
治疗学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Jie Chen,Jiafeng Wan,Chi Li,Yuhan Wei,Haolin Shi
Fe 0 -Fe 3 O 4 nanoparticles and cerium dioxide hollow spheres as efficient heterogeneous electro-Fenton reagents were rationally designed to be embedded in porous carbon derived from skimmed cotton for the electrocatalytic degradation of ceftriaxone sodium. Skimmed cotton porous carbon material has a hollow tubular structure, and cerium dioxide is dispersed on the surface of the carbon material in a hollow sphere structure of uniform size. Fe 0 -Fe 3 O 4 nanoparticles were wrapped in irregular particle shapes on the surface of cerium dioxide hollow spheres, and the remaining part was laid flat on the surface of porous carbon material. The as-synthesized Fe 0 -Fe 3 O 4 /CeO 2 /C showed excellent degradation efficiency of 95.59 % for ceftriaxone sodium within 120 mins and obtained a COD removal rate of 95.21 % at 240 mins. The zero-valent iron as a reducing agent effectively accelerated the Fe 3+ /Fe 2+ cycle, allowing the composites to exhibit higher catalytic activity and further reducing the possibility of secondary contamination. Moreover, the existence of cerium dioxide further promoted the redox cycle of Ce 4+ /Ce 3+ and accelerated the electron transfer in the interface of the catalyst. The synergistic effect of iron and cerium greatly facilitated the production of hydroxyl radicals and increased the yield of hydroxyl radicals in the reaction system.
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
危险品化学品经营许可证（带存储）