INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
·
IF 4.084
Shanshan Qiao,Jia Guo,Di Wang,Liugen Zhang,Afaq Hassan,Tingxiang Chen,Chao Feng,Yi Zhang,Jide Wang
It is of great significance to explore a bifunctional catalyst that can produce both hydrogen and oxygen to accelerate the development of water-splitting technology. In this work, Co@CoO/NG was obtained via calcinating ZIF-67 and in-situ preparation process, which exhibited excellent performance (water oxidation AQE 10.22% at λ = 450 nm and oxygen production rate 543198 μmol g −1 h −1 and hydrogen production rate 330 μmol −1 g −1 h −1 ). A comprehensive analysis of SEM, XRD , TEM, UV–vis, EIS , and PL showed that Co@CoO/NG-7 prepared has a perfect skeleton and more crystal defects , which can provide more reactive sites. The core-shell structure Co@CoO has a synergistic effect with graphene, which is beneficial to the light absorption, separation of photo-generated charges. Meanwhile, cyclic experiments of water oxidation and water reduction showed that the catalyst exhibited high stability during the reaction process. This study has provided a universal strategy to design efficient bifunctional catalyst for water-splitting.
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
ChemNanoMat
·
2023
·Vol. 9
·期 3
·e202200521
·
IF 3.8
Xinjie Guo,Xingyu Gan,Yun Wang,Xiaoxia Lv,Fengxiang Wang,Shuxin Wang,Shan Peng
Graphical A Co/CoO@NC/CNT-10 catalyst was effectively synthesized using melamine-assisted pyrolysis with Co-MOF as the precursor. With the synergistic effect of metal species, oxygen defects and N-doped carbon nanotubes, the intrinsic activity and electron transfer ability of the catalysts were greatly improved, showing excellent electrocatalytic oxygen reduction performance. Low-cost and high-efficiency oxygen reduction reaction (ORR) electrocatalysts are the basis for large-scale applications of electrochemical energy storage and conversion technologies such as fuel cells and metal-air batteries. Herein, cobalt and oxygen vacancy-rich cobalt oxide encapsulated in nitrogen-doped carbon and carbon nanotubes (Co/CoO@NC-CNTs) have been prepared by direct solid-state pyrolysis of Co-MOF. The carbon morphology, oxygen vacancy content and type of nitrogen can be finely tuned by mixing Co-MOF with proper amounts of melamine. The optimized material has an interwoven CNT structure with abundant micro- and mesopores, suitable nitrogen type and certain number of oxygen vacancies and exhibiting outstanding ORR electrocatalytic performance in alkaline media with an onset potential of 0.96 V and a half-wave potential of 0.88 V vs RHE, which is higher than 20 wt% Pt/C, as well as being highly stable and well resistant to methanol.
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
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2023
·
IF 9.9
Yuan Shu,Tingkai Zhao,Weiyu Jia,Lei Yang,Xianghong Li,Guyue Feng,Yatao Li,Fa Luo
The combination of magnetic and dielectric materials followed by appropriate structure design is an effective approach to achieve high electromagnetic wave absorption properties. Here, crosslinked Co@CoO/reduced graphene oxide nanohybrids (CCRGO) were fabricated via a simple three-step method. The experimental results show that compared with previous works, the as-prepared CCRGO nanohybrids achieve higher electromagnetic wave absorption and broader effective bandwidth at a lower filler loading. The electromagnetic parameters and electromagnetic wave absorption performance could be apparently adjusted by controlling the adding content of graphene oxide (GO) and the reduction temperature. Among a series of samples, CCRGO3-650 nanohybrid yields the best electromagnetic wave absorption performance benefiting from the proper GO addition and reduction temperature. At a filler loading of 20 wt%, the maximal reflection loss reaches to −64.67 dB at a thickness of 2.53 mm and the effective bandwidth below −10 dB covers the whole X band at a thickness of 2.51 mm. The good performance may be ascribed to the advantages of the dielectric and magnetic component as well as the special crosslinked structure, which triggers a synergistic absorption mechanism including multiple reflection/scattering, interface polarization, dipole polarization, conductive loss, eddy current loss, exchange resonance in the electromagnetic wave dissipation process. The good electromagnetic wave absorption performance affirms the potential application of CCRGO nanohybrids in the field of stealth materials.
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
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Ke Yang,Ziying Li,Ying Zhang,Linlin Zang,Xu Wang,Qing Xu,Liguo Sun,Yanhong Zhang
Producing hydrogen by electrolyzing water has received increased attention. Nevertheless, a major challenge remains in the search for high performance hydrogen evolution reaction (HER) electrocatalysts . In this work, multi-walled carbon nanotubes (MWCNTs) capped by TpPa covalent organic framework (TpPa-COF) react with cobalt nitrate hexahydrate (Co(NO 3 ) 2 ·6H 2 O) to form a novel ternary one-body complex (MWCNTs@TpPa-COF@Co/CoO). Wherein, TpPa-COF is constructed from 2,4,6-Triformylphloroglucinol (Tp) and p -phenylenediamine (Pa) as structural units. This COF is relatively inexpensive, provides more coordination sites for metal loading, and is particularly stable in acidic and basic media. The results show that the composite material has high electrocatalytic HER activity in a potassium hydroxide (KOH) condition with an overpotential value of 28.8 mV and a Tafel slope of 69.07 mV dec −1 at a current density of 10 mA cm −2 . Meanwhile, the MWCNTs@TpPa-COF@Co/CoO showed excellent stability after 2000 cycles in alkaline media. The characterization demonstrated that the material provided low resistance during the charge transfer process, which resulted in improved electrochemical performance. In addition, the COF loaded with cobalt nanoparticles provided more active sites for the reaction. Thus, the synthesized MWCNTs@TpPa-COF@Co/CoO emerges turns out to be a Pt-free, stable and efficient HER electrocatalyst, holding significant promise for practical applications.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
IONICS
·
2017
·Vol. 24
·期 5
·1321-1328
·
IF 2.062
Zhou Rihui,Chen Yaqin,Fu Yuanyuan,Li Yanfei,Chen Shouhui,Song Yonghai,Wang Li
A novel graphene (G)-Co/CoO shaddock peel-derived carbon foam (SPDCF) hybrid was fabricated as anode materials for lithium-ion batteries. The preparation of G-Co/CoO SPDCF was according to the following two steps. Firstly, the dried shaddock peels were immersed into the mixture of Co(NO 3 ) 2 /graphene oxide for about 12 h. Then, the shaddock peels were taken out and heated at 800 °C for 2 h under N 2 atmosphere. The strategy is simple, low-cost, and environmentally friendly because the shaddock peel is abundant and renewable. The obtained G-Co/CoO SPDCF hybrid were carefully characterized by SEM, EDS, XPS, XRD, TGA, BET, TEM, and electrochemical techniques. The results showed that the carbonized shaddock peels had hierarchical porous nanoflakes structures and graphene was uniformly dispersed into the SPDCF. The nanosized Co/CoO was formed on the G-SPDCF. The resulted G-Co/CoO SPDCF hybrid could maintain a high capacity of 600 mA h g −1 at 0.2 A g −1 after 80 cycles, which was much higher than that of commercial graphite (372 mA h g −1 ). The enhanced performance might be ascribed to the existence of lots of uniform Co/CoO and the hierarchical G-SPDCF alleviating the mechanical stress during the process of lithiation/delithiation.
研究领域:
材料科学
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电化学
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纳米材料
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能源存储
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功能材料
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2021
·
IF 13.273
Peijing Guo,Zhangyi Xiong,Shaoyu Yuan,Kaihong Xie,Haijun Wang,Yongjun Gao
Developing photocatalysts with high efficiency and low cost for water splitting is significant in the production of hydrogen using solar energy. In this report, a low-cost and environmentally-friendly photocatalyst (Co-CN-500) is achieved through a simple calcination procedure with natural chitin and cobalt nitrate as raw materials. With Eosin Y as photosensitizer in triethanolamine (TEOA) solution, the hydrogen evolution rate of Co-CN-500 can reach 12.63 mmol g -1 h -1 , which is higher than that of commercial Pt-C (10.34 mmol g -1 h -1 ) and other reported cobalt-containing photocatalysts. Characterization results prove the hybrid structure of cobalt ingredients involving cobalt monoxide and metal cobalt is essential for excellent photocatalytic performance. DFT calculations confirm the free energy of hydrogen adsorption and work function on Co/CoO hybrid surface are smaller than on Co (111) and CoO (111), making it easier to form adsorbed H that then produce H 2 .
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
Nanoscale
·
2021
·Vol. 13
·期 35
·14854-14865
·
IF 7.79
Xiaoqin Ye,Jinchen Fan,Yulin Min,Penghui Shi,Qunjie Xu
The development of non-noble metal electrocatalysts toward the oxygen evolution reaction (OER) is a key challenge in advancing electrocatalytic water splitting, which is essential for the commercialization of clean and renewable energy. A covalent organic framework (COF) has a precise and controllable structure, high π–π conjugation, large surface area, and porosity and shows great potential as an OER electrocatalyst. However, the relative conductivity and inherent instability greatly limit the further improvement of its performance. Herein, imine-based COF-supported Co/CoO nanoparticles (Co/CoO@COF) were developed for the high-performance electrocatalytic OER. For the Co/CoO@COF catalyst, Co/CoO could form a conjugation effect with the COF, which can increase the electron cloud density of the delocalized large π bond, then improve the conductivity. The combination of Co/CoO and COF effectively enhances the structural stability of the catalyst and enriches the catalytic active sites. Under alkaline conditions, the Co/CoO@COF shows a very low overpotential of 278 mV at a current density of 10 mA cm−2, and a Tafel slope of 80.11 mV dec−1 which is better than that of commercial RuO2.
研究领域:
材料科学
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能源化学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Today Nano
·
2026
·
IF 7.6
Yu Xiao,Yuheng Wang,Jingjing Zheng,Song Gao,Haojie Li,Yingyuan Zhao,Xiubo Xie,Chuanxin Hou,Wei Du
Fabricating electromagnetic coupling carbon-based aerogels with tightly bound and uniformly distributed components is a proven strategy for improving electromagnetic wave absorption (EWA) performance. Herein, highly ordered porous cobalt/cobalt (II) oxide/carbon (Co/CoO/C) aerogels were successfully fabricated via ice-templated freeze casting coupled with one-step carbonization, relying on the complexation reaction between cobalt ions and chitosan. The optimal sample, Co/CoO/C-1.0, achieves a minimum reflection loss (RL m ᵢ n ) of −58.15 dB and an effective absorption bandwidth (EAB) of 6.48 GHz at a thickness of 2.2 mm. Additionally, the aerogel exhibits excellent radar stealth performance (with a significant reduction in radar cross-section, RCS) and thermal insulation properties. Gradient structural design effectively extends the effective absorption bandwidth (EAB) to 11.23 GHz. Mechanism analysis reveals that the outstanding EWA performance of these aerogels stems from the synergistic effect of diverse attenuation pathways, including multiple scattering, dipole polarization, interfacial polarization, conduction loss and magnetic resonance. The regulation of cobalt content effectively achieves an optimal balance between impedance matching and electromagnetic loss. This multifunctional Co/CoO/C aerogel integrating EWA, radar stealth and thermal insulation capabilities possess great application prospects under complex service conditions and provide critical guidance for the rational design of carbon-based EWA absorbers. The highly ordered porous electromagnetic coupling Co/CoO/C aerogel was synthesized. The optimized aerogel achieves a minimum reflection loss (RL m ᵢ n ) of −58.15 dB and an effective absorption bandwidth (EAB) of 6.48 GHz at a thickness of 2.2 mm. The gradient multilayer structural design effectively broadens the effective absorption bandwidth (EAB) to 11.23 GHz. Download: Download high-res image (393KB) Download: Download full-size image
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产品关联
DOI
高影响因子
LANGMUIR
·
2026
·
IF 4.4
Long Cheng,Fan Yin,Chunmin Xu,Junhong Lin,Hailong Lu
In the current study, N-doped apple tree branch-based biochar-supported Co/CoO catalyst (Co/CoO@NBCs) was prepared using an impregnation-pyrolysis synergistic strategy, which addressed the issues of easy aggregation, poor stability, and low specific surface area of the Co/CoO catalyst. The characterization results show that Co/CoO@NBCs has a large specific surface area (1871.02 m2/g), a developed pore structure (0.99 cm3/g), and Co exists in the form of Co atoms and CoO. Under conditions of 0.25 mM peroxymonosulfate (PMS), 10 mg of catalyst, and room temperature, the degradation rate of norfloxacin (NOR, 30 mg/L) reached equilibrium within 70 min, with a removal rate of 99.06%. Besides the strong alkali condition (pH = 11) and the presence of HCO3–, the removal rate of NOR by Co/CoO@NBCs in other pH ranges and in anionic environments can still exceed 73%. Furthermore, analysis of the degradation mechanism shows that the active sites of Co0 and Co2+ can activate PMS to produce reactive oxygen species, with O2–• and 1O2 serving as the main active substances involved in NOR degradation. Additionally, tests with real water systems and cycling experiments further demonstrate that Co/CoO@NBCs have practical application potential. This work offers new insights into designing heterogeneous catalysts with multiple active sites for wastewater treatment.
✓ 已验证
DOI
PubMed
高影响因子
LANGMUIR
·
2026
·
IF 4.4
Xinru Nie,Qinghai Cai,Yajing Wang
Designing advanced cobalt-based catalysts capable of selectively generating singlet oxygen (1O2) is crucial for suppressing interference from coexisting reactive oxygen species in peroxymonosulfate (PMS) activation and achieving efficient degradation of organic pollutants. In this work, an interface engineering strategy was employed to fabricate Co-CoO-Co3O4/CN featuring abundant oxygen vacancies and Co active sites. The constructed Co-CoO-Co3O4/CN + PMS system achieves nearly complete degradation of 50 mg·L–1 RhB within 20 min, and its catalytic activity outperforms most reported cobalt-based catalysts, with a specific rate constant value as high as 11.23 L2·min–1·g–2. In addition, the Co-CoO-Co3O4/CN + PMS system exhibits excellent broad-spectrum applicability, outstanding environmental tolerance, and stability. It enables continuous treatment of 49.8 L of RhB solution, with the degradation efficiency consistently maintained above 99%. Systematic investigations demonstrate that Co-CoO-Co3O4/CN exhibits a strong interaction with PMS, and this enhanced interaction can drive the efficient conversion of PMS into superoxide anion radicals (O2•–), which are further transformed into 1O2. This work provides new insights into the rational design of high-performance cobalt-based catalysts, and paves the way for efficient PMS activation and selective 1O2 generation.
✓ 已验证
DOI
PubMed
高影响因子
ENVIRONMENT INTERNATIONAL
·
2019
·
IF 7.943
Min Sun,Yu Zhang,Hui-Hui Liu,Feng Zhang,Lin-Feng Zhai,Shaobin Wang
Oxygen (O 2 ) in air is an eco-friendly and economical oxidant. However, its activation is an energy-intensive process requiring high operation temperature. Herein, we report the synthesis of nanoscaled Co-CoO on a graphite felt (GF) as an anode material for electrocatalytic wet air oxidation (ECWAO) of water contaminants at room temperature. Such an ECWAO process shows extensive effectiveness in mineralizing a variety of biorefractory organic pollutants. A probe pollutant, bisphenol A (BPA), is rapidly degraded in 180 min with mineralization efficiencies higher than 85% over a wide pH range from 3.0 to 11.0. The Co-CoO/GF electrode exhibits excellent stability in the ECWAO process, without loss of activity and leaching of metal. The ECWAO process is confirmed to be initiated by the electrochemical activation of O 2 through a non-radical pathway. The CoO on the surface of Co nanoparticle is identified as the catalytically active site, at which O 2 molecules are first converted to chemisorbed oxygen species and then electrochemically oxidized to their activated states. The ECWAO process with the Co-CoO/GF electrode presents the merits of high efficiency, low energy input and environmental friendliness, and has a great potential for practical wastewater treatment.
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Kaiqing Dai,Ning Zhang,Lili Zhang,Linxin Yin,Yafei Zhao,Bing Zhang
Designing a non-noble metal-based bifunctional electrocatalyst for simultaneously boosting both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is highly desirable, which is decisive for enhancing the efficiency of overall water splitting. Herein, inspired by the appropriate H atoms binding energy of Co metal, favorable OER reaction kinetics of cobalt oxides, and more efficient electron transfer of self-supported structure, Co/CoO anchored on N-doped carbon layer coated on carbon cloth (Co/CoO@NC@CC) is synthesized by a facile self-assembly-carbonization method. Remarkably, the Co/CoO@NC@CC exhibits much increased electrochemical activities toward both OER and HER with low overpotentials of 284 and 152 mV required to deliver the current density of 10 mA cm −2 , respectively, which are superior to most of the reported Co-based and CoO-based catalysts. More importantly, the fabricated Co/CoO@NC@CC‖ Co/CoO@NC@CC electrolyzer only needs a small cell voltage of 1.66 V for driving overall water splitting to achieve the current density of 10 mA cm −2 . Moreover, the Co/CoO@NC@CC behaves superior stability after 25 h of continuous operation. Excellent features including the synergistic effect between Co and CoO, unique hierarchical porous structure, and self-supported construction jointly impart Co/CoO@NC@CC highly elevated bifunctional electrocatalytic activities.
研究领域:
材料科学
·
电化学
✓ 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）