INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2017
·
IF 3.582
Haiyan Shen,Dawei Ni,Ping Niu,Yi Zhou,Tianyou Zhai,Ying Ma
Spatially controlled co-loading of both oxidation and reduction cocatalysts on semiconductor photocatalysts has been demonstrated to be favorable for photogenerated charge separation and thus enhanced photocatalytic activity. Herein, we presented a simple ball-milling method to improve photocatalytic H 2 production of TiO 2 by co-loading of oxidation cocatalyst Co 3 O 4 with reduction cocatalyst CuO , wherein the Co 3 O 4 loading amount was significant especially for TiO 2 loaded with sufficient or optimum CuO. In comparison with that on TiO 2 loaded with only CuO, the photocatalytic H 2 production from water over TiO 2 photocatalyst co-loaded with CuO and trace Co 3 O 4 was enhanced by approximately 5.5 times, even though complex spatial control was not adopted. In contrast, remarkable improvement of photocatalytic activity after Co 3 O 4 co-loading was only observed on TiO 2 photocatalysts loaded with less CuO in the presence of methanol. Better separation of photogenerated charges on the surface of dual-cocatalysts modified TiO 2 was further demonstrated by decreased luminescence as well as increased photogenerated electrons and hydroxyl radicals as compared to those loaded with only CuO.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Xin Wang,Baofang Jin,Ruixue Feng,Wei Liu,Duan Weng,Xiaodong Wu,Shuang Liu
In this work, tandem oxygen delivery systems were built by coating cube-like Co 3 O 4 with Ag/CeO 2 , which exhibited high soot oxidation activity that overwhelmed the Fe 2 O 3 -based catalysts. The results of TPR and activity tests indicated that a large amount of Co 3 O 4 lattice oxygen could be transferred into O x − with the assistance of Ag/CeO 2 . These active oxygen species accelerated the oxidation of soot and NO at low temperature. Furthermore, the Co 3 O 4 -CeO 2 synergy facilitated Co 3+ → Co 2+ transformation during reactions, resulting in boosted NO conversion and thereby NO 2 -assisted soot combustion at mild and high temperatures. Given the Ag/Co 3 O 4 @CeO 2 -type catalysts were low-cost, hydrothermally stable and could be fabricated via co-precipitation methods easily, they were highly promising for application in both gasoline and diesel particulate filters.
研究领域:
催化
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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
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Jinping Liang,Ling Fu
Persulfate-based advanced oxidation process (PS-AOP) is a promising technology for in-depth wastewater treatment. Here, Co 3 O 4 quantum dots (QDs) decorated hierarchical C@Co 3 O 4 (C@Co 3 O 4 -Q5) was prepared by a facile route. The crystalline structure, micrograph and chemical composition of C@Co 3 O 4 -Q5 were characterized by XRD, SEM, TEM and XPS. Taking Rhodamine B (RhB) as a model contaminant, the influences of process parameters on the degradation performance were evaluated. Detailed reaction kinetics investigation indicated that, at elevated temperatures higher than 30 °C, RhB degradation rate approximately follows this expression: r = 1.022 × 1 0 7 e x p ( - 47850 / R T ) [ R h B ] [ P M S ] 0.36 , whereas the real energies for catalytic activation ( Eac ) and heat activation ( Eah ) were 16.231 kJ·mol −1 and 31.62 kJ·mol −1 , respectively. Reactive oxygen species (ROS) quenching experiments and EPR tests suggested that not the general held radical SO 4 − but the downstream OH and the nonradical ROS 1 O 2 co-contribute to RhB mineralization. Meanwhile, PMS activation mechanisms referring to OH and 1 O 2 generation were elaborated based on XPS discussion. It was revealed that Co 3 O 4 quantum dots and oxygen functional groups and/or oxygen defects on carbon surface cooperate to generate ROS. Additionally, 5 successive cycles confirmed C@Co 3 O 4 -Q5′s high stability and reusability. These findings provided new insights into carbon-loaded QDs catalysts for PMS-mediated micropollutants removal.
研究领域:
环境科学
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材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 16
·3747
·
IF 4.2
Guanyu Chen,Weixin Zhang,Rongshu Zhu,Yanpeng Chen,Minghu Zhao,Mei Hong
Zeolite-based catalysts efficiently catalyze the selective catalytic reduction of NOxwith methane (CH4-SCR) for the environmentally friendly removal of nitrogen oxides, but suffer severe deactivation in high-temperature SO2- and H2O-containing flue gas. In this work, SSZ-39 zeolite (AEI topology) with high hydrothermal stability is reported for preparing CH4-SCR catalysts. Mild acid leaching with oxalic acid (OA) not only modulates the Si/Al ratio of commercial SSZ-39 to a suitable value, but also removes some extra-framework Al atoms, introducing a small number of mesopores into the zeolite that alleviate diffusion limitation. Additional Co3O4modification during indium exchange further enhances the catalytic activity of the resulting In-Co3O4/H-SSZ-39(OA). The optimized sample exhibits remarkable performance in CH4-SCR under a gas hourly space velocity (GHSV) of 24,000 h−1and in the presence of 5 vol% H2O. Even under harsh SO2- and H2O-containing high-temperature conditions, it shows satisfactory stability. Catalysts containing Co3O4components demonstrate much higher CH4conversion. The strong mutual interaction between Co3O4and Brønsted acid sites, confirmed by the temperature-programmed desorption of NO (NO-TPD), enables more stable NxOyspecies to be retained in In-Co3O4/H-SSZ-39(OA) to supply further reactions at high temperatures.
研究领域:
环境科学
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催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Today Energy
·
2021
·
IF 7.311
Lina Yan,Xing Cheng,Yueshuai Wang,Zhaozhao Wang,Lirong Zheng,Yong Yan,Yue Lu,Shaorui Sun,Wenge Qiu,Ge Chen
The electrochemical production of hydrogen peroxide via the two-electron (2e − ) oxygen reduction reaction (ORR) is an environmentally friendly method and is expected to be an alternative means to the industrial anthraquinone process. It is particularly suitable for on-site and small-scale H 2 O 2 requirements. The development of earth-abundant catalysts with high activity and selectivity toward H 2 O 2 is highly desirable and challenging. Here, we have prepared Co 3 O 4 with tunable oxygen vacancies (OVs) and strongly coupled it to nitrogen-doped carbon nanotubes through an exsolution strategy. The Co 3 O 4 with a higher OV concentration exhibits a higher 2e − ORR activity, higher H 2 O 2 selectivity, and lower H 2 O 2 reduction reaction (H 2 O 2 RR) activity so that effectively improving the production rate of H 2 O 2 (1.6 mol peroxide/g catalyst /h at 0.0 V RHE ) in acidic media. The catalyst is also used as a cathode for the electro-Fenton process and degrades up to 80% of 40 mg/L of rhodamine B solution within 25 min. Density functional theory calculation shows that the ∗ OOH binding energy (Δ G ∗OOH ) could decrease on increasing the numbers of OVs, which subsequently benefits the protonation of ∗ OOH to generate H 2 O 2 .
研究领域:
材料科学
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电化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
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IF 5.116
Anni Li,Congwei Wang,Huinian Zhang,Zheng Zhao,Jie Wang,Miao Cheng,Huifang Zhao,Junying Wang,Minghong Wu,Junzhong Wang
Electrochemical water splitting by a robust electrocatalyst plays a key role in hydrogen production for clean and sustainable energy. In this work, a kind of nanohybrid of graphene supported atomic Co and nanocrystalline Co 3 O 4 was synthesized through electrochemical synthesis of atomic cobalt onto graphene using 1-Butyl-3-methylimidzolium tetrachlorocobalt [(BMIm) 2 CoCl 4 ] as an electrolyte. By virtue of the synergistic effect of single-cobalt atoms and Co 3 O 4 nanoparticles , the nanohybrid presents enhanced electrocatalytic performance toward the oxygen evolution reaction. The low onset potential is 0.49 V (vs. Ag/AgCl) and the overpotential of the current density of 10 mA cm −2 is 0.30 V in aqueous solution, which is comparable to commercial RuO 2 . Moreover, the nanohybrid exhibits remarkably long stability for over 45 h at a fixed potential of 0.6 V.
研究领域:
材料科学
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能源科学
✓ 已验证
DOI
高影响因子
SN Applied Sciences
·
2019
·Vol. 1
·期 3
·1-10
·
IF 0
He Shiwei,Xu Ruidong,Guo Yuqing,Zhao Zhuo,Yu Bohao,Xiao Saijun,Lv Huihong
In this study, β-PbO 2 –Co 3 O 4 composite coatings were synthesized on a substrate using the electrodeposition method in an electrolyte containing Pb 2+ and Co 3 O 4 particles. The preparation process study shows that the β-PbO 2 bath containing Co 3 O 4 particles becomes more stable for an ultrasonic dispersion time within 30 min, with the stability beginning to decrease after the ultrasonic time exceeds 30 min. Co 3 O 4 particles in the β-PbO 2 bath are positively charged, with anions being adsorbed onto the particles. The nucleation behavior study shows that the electric field force plays a dominant role in the adsorption process for the Co 3 O 4 particles. The nucleation and growth of β-PbO 2 on the Co 3 O 4 particles started for the particles closer to the substrate. In addition, the thickness of the β-PbO 2 layer on the Co 3 O 4 particles was inversely proportional to the distance between the Co 3 O 4 particles and the substrate. Compared to the pure PbO 2 electrode, the oxygen evolution overpotentials for the β-PbO 2 –Co 3 O 4 electrode are decreased significantly, which demonstrates an energy-saving effect.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2021
·
IF 4.539
Na Zhang,Enqi Liu,Hongwei Chen,Jinhui Hou,Chao Li,Hongri Wan
In order to solve the problem of low capacity and volume expansion of LaCoO 3 , LaCoO 3 /Co 3 O 4 perovskite composites were effectively fabricated by a simple hydrothermal method coupled with calcination process. When the calcination temperature is 800 °C, due to the nanoscale sizes, mesoporous structure and heterogeneous components, the samples (named LaCoO 3 /Co 3 O 4 -800) exhibit excellent lithium storage performance as lithium ion batteries (LIBs) anodes. LaCoO 3 /Co 3 O 4 -800 anode exhibits a high reversible capacity (549.7 mAh/g after 100 cycles at 100 mA/g) and superior cycling stability (396.7 mAh/g after 1000 cycles at 1 A/g). This research provides potential candidates for perovskite lanthanide nanomaterials for LIBs anodes.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 10
·1695
·
IF 5.719
Haodong Wen,Wenning Zhao,Xiuxun Han
Layered perovskite-type semiconductor La2Ti2O7has attracted lots of attention in photocatalytic hydrogen evolution, due to the suitable energy band position for water splitting, high specific surface area, and excellent physicochemical stability. However, the narrow light absorption range and the low separation efficiency of photogenerated carriers limit its photocatalytic activity. Herein, plate-like La2Ti2O7with uniform crystal morphology was synthesized in molten NaCl salt. A p-n heterojunction was then constructed through the in situ hydrothermal growth of p-type Co3O4nanoparticles on the surface of n-type plate-like La2Ti2O7. The effects of Co3O4loading on photocatalytic hydrogen evolution performance were investigated in detail. The results demonstrate that composite Co3O4/La2Ti2O7possesses much better photocatalytic activity than the pure component. The composite photocatalyst with 1 wt% Co3O4exhibits the highest hydrogen evolution rate of 79.73 μmol·g−1·h−1and a good cycling stability. The photoelectrochemistry characterizations illustrate that the improvement of photocatalytic activity is mainly attributed to both the enhanced light absorption from the Co3O4ornament and the rapid separation of photogenerated electron-hole pairs driven by the built-in electric field close to the p-n heterojunction. The results may provide further insights into the design of high-efficiency La2Ti2O7-based heterojunctions for photocatalytic hydrogen evolution.Keywords:photocatalysis;hydrogen evolution;p-n heterojunction;La2Ti2O7;Co3O4
研究领域:
材料科学
·
光催化
·
能源材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CRYSTENGCOMM
·
2017
·Vol. 20
·期 5
·679-688
·
IF 3.474
Huihui Chen,Mei Yang,Sha Tao,Guangwen Chen
A facile, template-free and easily scalable approach has been developed for the preparation of Co3O4 nanorings, which can be divided into two stages: (1) formation of CoOOH nanorings and (2) high-temperature calcination of CoOOH nanorings in air. The key step for the synthesis of Co3O4 nanorings is the formation of CoOOH nanorings, prepared by the oxidation of β-Co(OH)2 nanoplates with H2O2 under strong basic conditions. The plausible growth mechanism governing the formation of CoOOH nanorings was correlated with Ostwald ripening. It was found that the dosage of H2O2 played a vital role in the formation of CoOOH nanorings. To a large extent, other experimental variables including the H2O2 concentration, Co2+ concentration, the molar ratio of Co2+ to OH− and the reaction temperature did not affect the preparation of the CoOOH nanorings. Furthermore, the as-prepared Co3O4 nanorings exhibited superior activity in comparison with Co3O4 nanoplates and commercial Co3O4 towards the catalytic decomposition of H2O2. The apparent rate constant of the as-prepared Co3O4 nanorings was 0.38 min−1, which is 2.2 times the value of Co3O4 nanoplates.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2023
·Vol. 13
·期 6
·1073
·
IF 5.3
Shuangyin Zeng,Shaojie Han,Xiaotian Sun,Li Wang,Yanfeng Gao,Zhang Chen,Haitao Feng
Carbon materials derived from natural biomaterials have received increasing attention because of their low cost, accessibility, and renewability. In this work, porous carbon (DPC) material prepared from D-fructose was used to make a DPC/Co3O4composite microwave absorbing material. Their electromagnetic wave absorption properties were thoroughly investigated. The results show that the composition of Co3O4nanoparticles with DPC had enhanced microwave absorption (−60 dB to −63.7 dB), reduced the frequency of the maximum reflection loss (RL) (16.9 GHz to 9.2 GHz), and had high reflection loss over a wide range of coating thicknesses (2.78–4.84 mm, highest reflection loss <−30 dB). This work provided a way for further research on the development of biomass-derived carbon as a sustainable, lightweight, high-performance microwave absorber for practical applications.Keywords:biomass porous carbon;Co3O4;microwave absorbing;impedance matching;dielectric loss
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Energy Materials
·
2024
·
IF 5.4
Yi-Fu Huang,Mao-Jin Ran,Zhi-Rong Li,Man-Man Yuan,Ting-Ting Shen,Kai Liu,Ze-Yu Jiang,Shokir Khojiev,Zhi-Yi Hu,Jing Liu,Li-Hua Chen,Yu Li,Bao-Lian Su
The conversion of solar energy into hydrogen (H2) through photocatalysis technology has been considered to be one of the most promising ways to alleviate the energy crisis. However, achieving efficient H2 production is still a big challenge due to the rapid recombination of photogenerated carriers. In this work, we direct Mn0.2Cd0.8S/Co3O4 np junctions via in situ growing p-type Co3O4 nanoparticles on the surface of n-type Mn0.2Cd0.8S nanorods for photocatalytic hydrogen production. Compared to ex-situ-grown samples, the in-situ-grown samples construct many more channels for photogenerated charge carrier transfer via the np junctions and built-in electric field to promote their separation and migration, leading to enhanced photocatalytic hydrogen production. The results show that Mn0.2Cd0.8S/Co3O4-20 exhibits a H2 production rate of 26.98 mmol h–1 g–1 under visible light, which is about 2.71 times higher than that of pure Mn0.2Cd0.8S. In addition, the apparent quantum efficiency at 450 nm of Mn0.2Cd0.8S/Co3O4-20 reaches 14.0%. Our work here provides insights into constructing heterojunctions to facilitate photogenerated charge separation and transfer for photocatalysis and photovoltaic applications.
研究领域:
材料科学
·
能源科学
·
光化学
✓ 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）