APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Ruixiang Deng,Bingbing Chen,Haogeng Li,Ke Zhang,Tao Zhang,Yun Yu,Lixin Song
Microwave absorbers serve the purpose to ensure the transmission efficiency and accuracy in 5G telecommunications. Two-dimensional MXene has great potential in absorbing microwave. In this study, MXene(Ti 3 C 2 T x )/Co 3 O 4 composites are successfully fabricated by a facile and stable hydrothermal treatment in concentrated strong base and Argon environment, followed by a one-step annealing process. Phase composition , chemical state of elements, morphology and structure of the new composite materials are studied by systematical characterization. It is revealed that adsorbed Na + ions and terminations, which are generated at the interface during hydrothermal treatment in concentrated NaOH solution, can protect the Ti 3 C 2 T x from being decomposed. The synthesis mechanism is also proposed for stable fabrication of other MXene-based composite materials. The MXene/Co 3 O 4 composite is able to perform single-band absorption, multiband absorption and even broadband absorption in 2–18 GHz band by tuning its composition and thickness. Particularly, better than 90% absorption in a wide range of 10.8–17 GHz can be achieved with a thickness of just 2 mm. Enhanced wideband absorption originates from the multilayer structure , the surface defects , the conductivity of Ti 3 C 2 T x and the capacitance structure of Co 3 O 4 . Ultrathin and broadband high absorption features make the material a promising candidate for future application.
研究领域:
材料科学
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电磁材料
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通信技术
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2018
·
IF 11.698
Weiyi Chen,Bin Han,Chen Tian,Xueming Liu,Shujie Liang,Hong Deng,Zhang Lin
Reducing carbon dioxide (CO 2 ) to various value-added chemical products by photocatalysis could effectively alleviate the serious problems of global warming and energy shortages. Currently, most commonly prepared photocatalysts present poor performance under visible light irradiation. In this study, we adopted a facile, scalable and controllable approach to prepare ultrathin two-dimensional (2D) porous Co 3 O 4 catalysts (Co 3 O 4 -NS) by air calcining of the ultrathin metal-organic framework (MOFs) nanosheet templates to validly reduce CO 2 with a Ru-based photosensitizer under visible light irradiation. Benefitting from the structural nature of MOFs precursors, the calcined Co 3 O 4 -NS inherit the morphology of 2D and well-developed porosity, which support the transport of electrons, enhance the adsorption of CO 2 molecules, and render abundant catalytic sites for CO 2 activation. As a result, the CO generation rate is approximately 4.52 μmol·h −1 with selectivity of 70.1%, which is superior to the Co 3 O 4 bulk catalysts (Co 3 O 4 -BK). Additionally, density functional theory (DFT) calculations reveal that the model of Co 3 O 4 monolayer has stronger CO 2 adsorption energy than that of the Co 3 O 4 bulk, which is beneficial for the CO 2 -to-CO conversion. This MOF-engaged strategy provides new insight into the controlled synthesis of advanced ultrathin holey nanosheets to improve the efficiency of photocatalytic CO 2 reduction.
研究领域:
材料科学
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环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
DIAMOND AND RELATED MATERIALS
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2022
·
IF 3.806
Ruyi Zou,Baoli Wang,Lin Zhu,Lijun Yan,Fan Shi,Yunxiu Sun,Bo Shao,Siyue Zhang,Wei Sun
Carbon based composites derived from various biomasses have exhibited excellent application prospects in the field of supercapacitors . Herein, the Co 3 O 4 nanoparticles supported on biomass eggfruit-derived porous carbon (EPC) was prepared via solvothermal method and subsequent calcination , in which the shells of eggfruit's kernel (SEK) were used as carbon source and cobalt phthalocyanine was employed as precursor of Co 3 O 4 . The resultant composite was denoted as Co 3 O 4 @EPC and its supercapacitive performances were checked in details. Scanning electron microscopy and transmission electron microscopy images of Co 3 O 4 @EPC show that EPC has a three-dimensional porous network structure, and Co 3 O 4 nanoparticles with an average particle size of 7 nm are uniformly dispersed on the EPC carrier. In the three-electrode system with 6 mol L −1 KOH as electrolyte, the specific capacitance of Co 3 O 4 @EPC/Ni foam electrode is 781 F g −1 at the current density of 0.5 A g −1 , which is much higher than that of p-Co 3 O 4 electrode (429.69 F g −1 at 0.5 A g −1 ) or EPC (125.39 F g −1 at 0.5 A g −1 ) electrode under the same conditions. The energy density of a two-electrode device with Co 3 O 4 @EPC/Ni foam electrode as positive electrode and EPC/Ni foam electrode as negative electrode was 32.8 Wh K g −1 at the power density of 1333 W K g −1 . In addition, the device has good cyclic stability with a capacitance retention rate of 96.7% after 20,000 cycles. These results indicate that the excellent properties of the Co 3 O 4 @EPC make it a potential electrode material for high-performance supercapacitors .
研究领域:
材料科学
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能源存储
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Shuo Li,Yahui Li,Juan Zhang,Xiutao Liu,Kaixin Zhang,Yu Zhang,Xi-ming Song
A CoOOH cocatalyst overlayer is electrochemically deposited on the BiVO 4 surface, and thermal annealing converted CoOOH to Co 3 O 4 in situ. The primary difference between the two cocatalysts lies in their electrolyte permeabilities, resulting in significant differences in their thermodynamic effects on enhancing the photoelectrochemical water oxidation performance. We proved that the CoOOH cocatalyst is unable to achieve true chemical passivation of the surface states of the BiVO 4 photoanode, whereas the Co 3 O 4 cocatalyst can chemically passivate the surface states. Nevertheless, the CoOOH cocatalyst still exhibits better water oxidation performance than Co 3 O 4 , which is attributed to the fact that the permeable CoOOH cocatalyst can accumulate more photogenerated holes in the bulk phase and provide more active sites. However, the CoOOH cocatalyst still exhibits better water oxidation performance compared to Co 3 O 4 , which is attributed to the permeable CoOOH cocatalyst can accumulate more photogenerated holes in its bulk phase and offer more active sites.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Tianguan Wang,Xiankang Zhong,Zhi Zhang,Xi Yuan,Li Zhou,Ziqi Zheng,Abdolreza Farhadian,Junying Hu
Asphaltene precipitation could have several negative consequences, including production decline, wellbore plugging, and even severe safety concerns. Therefore, an effective strategy of asphaltene adsorption is highly significant. Nanoparticles possess a large surface area, showing a high adsorption potential for asphaltene. However, the self-aggregation property limits its adsorption capacity. In this work, the Co 3 O 4 nanoparticles were ingeniously selected as an inhibitor of asphaltene precipitation, and a porous SiO 2 film was formed via the sol-gel method. The evaluation experiments indicated that the SiO 2 film significantly reduced the self-aggregation. Hence, the specific surface area of nanoparticles increased from 20.87 m 2 /g to 29.25 m 2 /g. Meanwhile, molecular dynamics simulations confirmed that the modified nanoparticles exhibited 1.6 times higher adsorption energy and a lower mean square displacement than the fundamental nanoparticles. With these improvements, the Co 3 O 4 -SiO 2 nanoparticles developed greater stability and dispersion, which raised the adsorption of the nanoparticles on asphaltene from 1.24 mg/m 2 to 1.53 mg/m 2 , presenting a considerable adsorption capacity. This study broadens the selection of nanoparticles for asphaltene adsorption. It demonstrates the improvement of nanoparticles by porous SiO 2 film in various aspects, which can provide a solution for inhibiting asphaltene precipitation in oil fields as well as guidance for subsequent functionalization of nanoparticles.
研究领域:
石油工程
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材料科学
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化学工程
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2023
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IF 8.4
Liupeng Zhao,Rongrong Jin,Chen Wang,Tianshuang Wang,Yanfeng Sun,Peng Sun,Geyu Lu
In this work, we successfully prepare the ZnO-Co 3 O 4 heterostructure on a nanosheet hollow sphere structure. Due to the high redox activity of Co 3 O 4 , the fabricated sensor using 3 at% ZnO-Co 3 O 4 hollow composite exhibits enhanced acetone sensing performance (S = 17.3–50 ppm) at a low operating temperature (150 °C), which is about 5.1 times higher than that of Co 3 O 4 -based sensor (S=3.4–50 ppm). Meanwhile, the ZnO-Co 3 O 4 based sensor shows ppb-level detection limit (S=1.3 at 100 ppb). The reason for the higher sensitivity and lower detection limit of the sensor is that the formation of n-p heterojunctions reduces both the degree of upward band-bending and the surface hole concentration, that allows the sensor to have a higher gas response under the same surface sensing-reactions (surface charge transfer).
研究领域:
材料科学
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传感器技术
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2024
·Vol. 59
·期 44
·20624-20639
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IF 3.5
She Houde,Chen Dongxu,Huang Jingwei,Wang Lei,Chen Jiufu,Chen Xiaoping,Wang Qizhao
The removal of volatile organic compounds has been a long-standing challenge, and NH 2 -MIL125, with its large specific surface area, has shown great promise in this regard. However, its limited number of active sites hinders its widespread application. To address this limitation, we report the successful synthesis of a series of Co 3 O 4 -modified NH 2 -MIL125 metal–organic framework (MOF) composites with a lamellar structure. Notably, the optimized 35% Co 3 O 4 /NH 2 -MIL125 composite exhibited exceptional performance, achieving 85.59% degradation and 76.58% CO 2 conversion under simulated sunlight. Moreover, this composite demonstrated excellent stability, maintaining a degradation rate of 79.67% over 520 min. The enhanced performance is attributed to the large specific surface area of NH 2 -MIL125, as well as the Co 3 O 4 modification, which provides new active sites, enhances light utilization efficiency, accelerates the separation of photogenerated carriers, and facilitates the generation of reactive radicals. This in-situ growth strategy for modifying NH 2 -MIL125 with Co 3 O 4 offers a novel approach to expand the application scope of NH 2 -MIL125 and enhance its performance in toluene degradation. Graphical abstract
Characterization of layered Co 3 O 4 -modified NH 2 -MIL125 catalysts, evaluation of photocatalytic degradation performance of toluene, photogenerated carrier migration, and separation studies.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2018
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IF 6.735
Liwei Chen,Shengjiong Yang,Xu Zuo,Yang Huang,Tianming Cai,Dahu Ding
Extraordinary activation of peroxymonosulfate (PMS) was achieved by Co 3 O 4 fabricated with assistance of rice straw derived biochar (BC-Co 3 O 4 ). The introduction of biochar significantly improved the specific surface area (from 37.0 to 62.7 m 2 /g). The BC-Co 3 O 4 /PMS system showed an excellent performance for the degradation of antibiotics (ofloxacin, OFX in this case). The evolution of radical species was monitored with electron paramagnetic resonance (EPR) technique. Both SO 4 − and OH contributed to the degradation process and the latter one played a major role. The radicals were mainly generated through heterogeneous mechanism rather than homogeneous process. The effects of experimental conditions (initial pH value, dose of PMS, naturally occurring inorganic anions) on the degradation process were systematically investigated. Eventually, the X-ray photoelectron spectroscopy (XPS) results suggested that the large amounts of Co-OH groups on BC-Co 3 O 4 might be the reason of the extraordinary activity. The findings obtained from this study might be meaningful to enlarge the applications of biochar.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2018
·Vol. 6
·期 29
·14431-14439
·
IF 9.931
Qianqian Zhou,Ting-Ting Li,Jinjie Qian,Yue Hu,Fenya Guo,Yue-Qing Zheng
The preparation of low-cost and efficient bifunctional catalysts towards water splitting is essential for the production of clean H2 energy. Herein, a hierarchical Co3O4-decorated CuO–Cu2O nanorod core–shell structure was in situ grown on a Cu foam (denoted as CuOx@Co3O4 NRs/CF) and investigated as a bifunctional catalyst for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline solution. Benefiting from its large electrochemical surface area and the synergetic effects between the CuOx core and Co3O4 shell, CuOx@Co3O4 NRs/CF exhibited considerable catalytic activity, which resulted in a small overpotential of 240 mV for the OER and 242 mV for the HER at a current density of 50 mA cm−2, along with low Tafel slopes of 46 and 61 mV dec−1, respectively. Remarkably, CuOx@Co3O4 NRs/CF could continuously produce O2 or H2 for at least 24 h with negligible decline in catalytic activity, and it gave rise to high faradaic efficiencies of 99.7% and 96.4% for the OER and HER, respectively. The electrochemical performance of CuOx@Co3O4 NRs/CF was dramatically improved as compared to those of its CuOx NRs/CF counterpart and also most reported Cu-based water splitting electrocatalysts.
研究领域:
材料科学
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能源化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2017
·
IF 6.844
Shanshan Liu,Xu Zhao,Yanbin Wang,Huixin Shao,Meng Qiao,Yan Wang,Shen Zhao
In this paper, a photoelectrocatalytic (PEC) system consisting of γ-Bi 2 MoO 6 anode and Co 3 O 4 loaded carbon fiber paper (Co 3 O 4 /CFP) cathode prepared by a hydrothermal method was established and used to degrade phenol . In order to enhance the PEC degradation efficiency of phenol, peroxymonosulfate (PMS) was introduced into this system. At an applied bias of 1.5 V, the removal efficiency of 10 mg/L phenol was increased from 6% to 100% with 2 mM PMS addition into the PEC process. The degradation rate constant of phenol was also increased to be 0.0496 min −1 . Effects of PMS concentration, applied bias and initial pH were investigated. Based on the ESR analysis, sulfate radicals (SO 4 − ) and hydroxyl radicals (HO ) were proved to be the dominant oxidizing species for phenol degradation in the combined system. The PMS was activated to generate SO 4 − by loaded Co 3 O 4 , in which photogenerated-electrons accelerated the cobalt cycle process on the cathode. As a result, Co leaching was largely inhibited. The stability of the PEC system for organics degradation was exhibited.
研究领域:
环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2019
·
IF 5.108
Hai Chen,Jianlong Wang
In this study, Fe 3 O 4 /Co 3 O 4 composites were prepared and applied in the catalytic ozonation of sulfamethoxazole (SMX). Various parameters including initial solution pH, Fe 3 O 4 /Co 3 O 4 composites dose, O 3 dose and SMX concentration were investigated. Results showed that Fe 3 O 4 /Co 3 O 4 composites could significantly improve the mineralization of SMX by catalytic ozonation system and a synergic effect between Fe 3 O 4 and Co 3 O 4 was observed. Only about 16% total organic carbon (TOC) could be removed in 60 min by single ozonation under the condition of 20 mg/L SMX, 6.0 mg/min O 3 , pH 5.1 and room temperature, While in the presence of 0.10 g/L Fe 3 O 4 /Co 3 O 4 composites at the same conditions, 60% TOC removal were obtained by catalytic ozonation process. SMX could be degradation by O 3 rapidly and the removal was not significantly affected by the changing parameters. However, those operating parameters exerted different effects on SMX mineralization. Furthermore, the generation of hydroxyl radicals ( OH) and the utilization efficiency of O 3 would increase with the addition of Fe 3 O 4 /Co 3 O 4 composites. The quenching experiments indicated that OH might account for the enhancement of SMX mineralization and the mechanism of catalytic ozonation was proposed. Additionally, the intermediates were detected by using a high-performance liquid chromatography-mass spectrometry (LC-MS), from which some plausible transformation pathways were proposed.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL RESEARCH
·
2025
·
IF 7.7
KeXuan Wu,Jing Cao,Ran Zhang,Yong Pei,Ting Peng,Ge Chen
Co 3 O 4 has exhibited chlorine evolution reaction (CER) activity comparable to that of RuO 2 . However, it is plagued by relatively low catalytic activity and insufficient long-term stability. In the field of cobalt oxide doping, typically, a relatively large quantity of dopants is used to modulate its performance. In contrast, the exploration of doping with trace amounts of elements has been scarce. In this study, small amounts of Sn and Bi were introduced into the Co 3 O 4 electrocatalyst. The impacts of different doping ratios on the morphology and catalytic performance of the catalyst were systematically investigated. Under specific proportion conditions, the co-doping of these two elements with cobalt tetroxide demonstrated a remarkable synergistic effect. Moreover, a mechanism for the improvement of catalyst performance, based on DFT calculations, was proposed. Subsequently, the ammonia-nitrogen degradation capacity and long-term stability of the modified catalyst were evaluated through ammonia-nitrogen degradation experiments. The degradation mechanism was further elucidated using free-radical scavenging experiments.
研究领域:
环境科学
·
材料科学
·
电催化
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）