ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Liming Guo,Xin Wan,Jieyuan Liu,Xu Guo,Xiaofang Liu,Jiaxiang Shang,Ronghai Yu,Jianglan Shui
Synergistic effects have been applied to a variety of hybrid electrocatalysts to improve their activity and selectivity. Understanding the synergistic mechanism is crucial for the rational design of these types of catalysts. Here, we synthesize a MnCo2O4/Co–N–C hybrid electrocatalyst for the oxygen reduction reaction (ORR) and systematically investigate the synergy between MnCo2O4 nanoparticles and Co–N–C support. Theoretical simulations reveal that the synergy is closely related to the distance between active sites. For a pair of remote active sites, the ORR proceeds through the known 2e- + 2e- relay catalysis while the direct 4e– ORR occurs on a pair of adjacent active sites. Therefore, the formation of the undesired byproduct (H2O2) is inhibited at the interface region between MnCo2O4 and Co–N–C. This synergistic effect is further verified on an anion-exchange membrane fuel cell. The findings deepen the understanding of synergistic catalysis and will provide guidance for the rational design of hybrid electrocatalysts.
研究领域:
材料科学
·
电化学
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产品关联
DOI
PubMed
高影响因子
Journal of CO2 Utilization
·
2019
·
IF 5.189
Weiqi Liu,Zhichao Miao,Zhenbin Li,Xiaozhong Wu,Pengfei Zhou,Jinping Zhao,Huahua Zhao,Weijiang Si,Jin Zhou,Shuping Zhuo
A series of Co@N-C materials are synthesized from pyrolysis of ZIF-67 at different temperatures and employed as catalyst for electrochemical reduction of CO 2 (CO 2 RR) to syngas. Through a systematical investigation of the relationship between structure of Co@N-C catalysts and their catalytic activity, it could be found that the Co species exposed on the material surface mainly promote the hydrogen evolution reaction (HER) process to produce H 2 , while the Co particles packaged by N-C skeleton provide electrons and transfer them to CO 2 molecule through the Co -N- C skeleton, promoting the CO 2 reduction reaction. Following this thinking, the pristine Co@N-C materials are treated by aqua regia to remove the surface exposed Co species. After acid treatment, the affinity of H species sharply decreases, and adsorption of CO 2 and transfer of electron to CO 2 are successfully improved. The acid-treated Co@N-C catalysts exhibit improved catalytic activity, faradic efficiency of CO, and stability in CO 2 RR process. Among all these catalysts, the obtained Co@N-C-700-A shows highest CO 2 reduction activity and stability, achieving a specific current of 25 A∙g (cat) −1 and a productivity of 0.266 mol (CO) h −1 ∙ g(cat) −1 at a mild potential of -0.57 V vs. RHE. The ratio of CO/H 2 in products could be adjusted in the range of 1/4 to 1.5/1.
研究领域:
材料科学
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电化学
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催化
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能源转换
✓ 已验证
产品关联
DOI
高影响因子
Science Advances
·
2025
·Vol. 11
·期 9
·
IF 12.5
Mengxue Huang,Xuya Zhu,Wenwen Shi,Qianqian Qin,Jie Yang,Shanshan Liu,Lifang Chen,Ruimin Ding,Lin Gan,Xi Yin
Nitrogen-coordinated metal sites (MNx) in metal- and nitrogen-codoped carbon (M-N-C) catalysts offer promising electrocatalytic activity, but selective synthetic design of MNx sites with specific coordination environments remains challenging. Here, we manipulate the formation statistics of MNx sites by using sacrifice alkali metals (AM = Li, Na, and K) to form metal vacancy-Nx carbon (AM-MVNx-C) templates, which are used to direct the solution-phase formation of CoN4 sites in Co-N-C catalysts. We build a probability weight function based on the embedding energy of M in MNx sites as the descriptor for MNx formation statistics, and we predict that the alkali metals are prone to induce the formation of MVN4 sites. By coordinating Co2+ ions with AM-MVNx-C templates, we synthesize Co-N-C with CoN4 sites, demonstrating remarkable oxygen reduction activity in anion exchange membrane fuel cells. These results highlight the statistical thermodynamics of MNx formation and open up the possibility for the rational design of complex M-N-C electrocatalysts with well-defined MNx sites.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Inorganic Chemistry Frontiers
·
2023
·Vol. 10
·期 8
·2370-2379
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IF 7
Yanli Ruan,Hang Xu,Haikuo Lei,Wenjuan Xue,Tianyu Wang,Shidong Song,Yangyang Yu,Gui-Rong Zhang,Donghai Mei
Zn–air batteries (ZABs) have been widely studied due to their high theoretical energy density, low cost, and high safety. However, the lack of efficient bifunctional electrocatalysts toward both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) hinders their large-scale application. Herein, a dendritic NiS2@Co–N–C/CNF nanoarchitecture is proposed, which was fabricated by high-temperature carbonization of Co-MOFs and a subsequent simple hydrothermal composite method using NiS2 nanosheets. The catalyst is reasonably designed to integrate the oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) active sites on the surface of carbon nanofibers. Through the synergy between NiS2 and Co–N–C/CNF and the unique branch–leaf porous structure, the catalyst showed excellent catalytic activity and stability. In an alkaline electrolyte, the OER overpotential of NiS2@Co–N–C/CNF is 300 mV at 10 mA cm−2. The ORR half-wave potential (E1/2) of NiS2@Co–N–C/CNF is 0.8 V. In addition, the superior catalytic activity of NiS2@Co–N–C/CNF could be transferred to a ZAB, which exhibits a maximum peak power density of 181 mW cm−2 along with an ultra-long cycling stability for 1050 and 600 h at discharging current densities of 5 and 10 mA cm−2, respectively. The performance is significantly higher than that of commercial precious metal Pt/C + IrO2 mixed catalysts. The peak power density of solid state ZAB (SSZAB) integrated with NiS2@Co–N–C/CNF is 76 mW cm−2, and it can still maintain excellent cycling stability under different bending states. More impressively, four in-series SSZABs (NiS2@Co–N–C/CNFs) can charge smartphones, indicating their potential feasibility in the field of wearable electronics.
研究领域:
材料科学
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电化学
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能源存储与转换
✓ 已验证
产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2023
·Vol. 25
·期 6
·981-987
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IF 3.1
Nan Li,Minghao Shi,Wei Zhan,Wenjing Shen,Mianmian Wu,Guifang Sun,Qingfei Li,Jiangquan Ma
Ru-based catalysts are potential substitutes for Pt in the hydrogen evolution reaction (HER). It is worth noting that the Se ions in RuSe2 can modulate the electronic structure of the Ru metal, thus effectively improving the HER kinetics of RuSe2. However, single electronic structure modulation is hard to complete due to the electron deficiency of active Ru atoms. Herein, we prepare and design a novel RuSe2/Co–N–C (RuSe2 nanospheres supported on Co–N–C nanosheets) electrocatalyst with two-electron modulation by a hydrothermal and thermal annealing method. Benefiting from the uniform distribution of RuSe2 nanospheres on Co–N–C nanosheets and Co–N–C nanosheets acting as additional electron donors to make up for the electron deficiency of the Ru metal, RuSe2/Co–N–C exhibits excellent HER performance with a low overpotential of 26.4 mV at 10 mA cm−2 and a low Tafel slope of 53.2 mV dec−1. This work offers an effective method for the synthesis of high catalytic performance electrocatalysts by constructing an interaction between the carrier and the active metal.
研究领域:
材料科学
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电化学
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产品关联
DOI
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2022
·Vol. 414
·期 5
·1857-1865
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IF 4.478
Sun Liping,Yan Yong,Chen Shuai,Zhou Zijue,Tao Wei,Li Chao,Feng Yi,Wang Feng
Biothiol detection is of great importance for clinical disease diagnosis. Previous nanozyme-based colorimetric sensors for biothiol detection showed unsatisfactory catalytic activity, which led to a high detection limit. Therefore, developing new nanozymes with the high catalytic activity for biothiol detection is extremely necessary. Recently, single-atom nanozymes (SAzymes) have attracted much attention in biosensing due to their 100% atom utilization and excellent catalytic activity. Most previous works focus on the peroxidase-like activity of Fe-based SAzymes by using unstable and destructive H 2 O 2 as the oxidant. It is essential to develop new SAzymes with high oxidase-like activity for biosensing to break through the limitation. Herein, Co–N–C SAzymes with high oxidase-like activity are explored. Furthermore, Co–N–C SAzymes are used as a biosensor for colorimetric detection of biothiols (GSH/Cys) based on the inhibition of thiols toward the oxidase-like activity of Co–N–C SAzymes, which showed high sensitivity with a low detection limit of 0.07 µM for GSH and 0.06 µM for Cys. Besides, the method showed good reproducibility and high selectivity against other amino acids. This work offers new insights using Co–N–C SAzymes in the biosensing field.
研究领域:
生物传感
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医学诊断
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纳米材料
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2023
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IF 5.2
Ke Wu,Chunlei Wu,Wenou Bai,Ning Li,Yangqin Gao,Lei Ge
Hydrogen energy is vital important for solving pollution of environment and energy shortage. Hydrogen production via solar energy and semiconductor photo-splitting water is one of the most environmentally friendly strategies at present. In this work, Co-N-C, a non-noble metal-based ZIF-67 derivative, was employed as a co-catalyst to achieve an in situ growth of spherical CdS via simple one-step hydrothermal. Due to the large specific surface area of Co-N-C, the agglomeration of CdS is avoided and the photocorrosion phenomenon is weakened. Under irradiation of visible light , the hydrogen generation activity of Co-N-C/CdS was achieved 905 μmol g −1 h −1 . It is 6 times that of pure CdS with excellent stability. At the contact interface of the Co-N-C and CdS, the transfer and the separation of photoinduced carriers had been enhanced by a great many of channels. DFT calculation further showed that Co nanoclusters , as the active sites of hydrogen production, significantly enhanced photocatalytic hydrogen evolution activity. Therefore, Co-N-C not only acts as electron acceptor , but also serves as support of highly dispersed CdS to promote the stability of system during photocatalytic hydrogen generation. This work demonstrates the advantages of CdS binding MOF derivatives to construct composite photocatalysts with enhanced dispersibility and hydrogen production activity.
研究领域:
材料科学
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2023
·
IF 8.4
Jialu Pan,Man Li,Feng Zhang,Xiaoran Wang,Yanqing Cong,Shi-Wen Lv
It is of great significance to exploit simple and efficient methods for detecting hazardous substances in the fields related to food safety and environmental protection. Herein, for the first time, a newly-designed hollow Co-N/C nanocage with oxidase-like activity was synthesized via a feasible method. Benefiting from the construction of hollow structure and the introduction of carbon layer , the specific surface area of enzyme mimic was improved, so exposing more active sites. Importantly, hollow Co-N/C nanocage displayed an excellent performance in interfacial charge transfer, which provided convenience for the occurrence of chromatic reaction between enzyme mimic and TMB . As predicted, hollow Co-N/C nanocage can effectively oxidize colorless TMB to blue oxTMB in the absence of H 2 O 2 , and the analyses about catalytic mechanism suggested that both the redox couples of Co 3+ /Co 2+ and O 2 •− were involved in the oxidation of TMB. Furthermore, a chromogenic sensing method for the detection of Na 2 SO 3 and Cr 6+ was exploited, and a broad linear range and a low LOD can be achieved. More interestingly, developed detection method still possessed good recovery even in real samples. In a word, current work will share novel insights into the design of enzyme mimics and the analyses on chromogenic mechanism.
研究领域:
材料科学
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分析化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2025
·
IF 7.5
Wei Wen,Chunying Wang,Xudong Chen,Jingyi Wang,Yaobin Li,Fei Wang,Wenpo Shan,Ping Ning,Kai Li
Two-dimensional materials have garnered significant attention in the field of catalysis due to their high electron transfer efficiency. In this study, a quasi-two-dimensional carbon–nitrogen doped cobalt-based catalyst (Co-N-C (F)) was synthesized for the investigation of formaldehyde (HCHO) oxidation at room temperature. The electronic coordination structure of the catalyst was modified by varying the calcination temperature, resulting in the formation of Co-N 4 sites that enhance the degradation of the intermediate formate. Additionally, the quasi-2D structure formed during high-temperature pyrolysis retains characteristics of the ZIF 3D material, with a high specific surface area and a porous aggregation structure, which further enhances the exposure of active centers and diffusion of the feed gas. Characterization results showed that the number of Co-N 4 sites on the catalysts increases with the rise in pyrolysis temperature, with the Co-N-C (F)-1000 catalyst exhibiting the highest concentration of Co-N 4 sites. Activity test results indicated that the Co-N-C (F)-1000 catalyst achieved a 100 % HCHO removal rate at 25 °C, with WHSV 200,000 mL/(g·h). In contrast, the activity of the Co-N-C (F)-1100 catalyst decreased, which could be attributed to the aggregation of Co particles at excessively high temperatures. The HCHO oxidation mechanism of the Co-N-C (F) catalysts was investigated using in situ diffuse reflectance infrared spectroscopy ( in situ DRIFTS), and the reaction was found to follow the sequence HCHO → HCOO − → CO 2 + H 2 O, with formate degradation as a rate-limiting step.
研究领域:
催化材料
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环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
ANALYST
·
2022
·Vol. 147
·期 5
·915-922
·
IF 5.227
Jian Chen,Song Hu,Yongliang Cai,Xia Liu,Yueqi Wu,Yihu Dai,Zhijuan Wang
Nanozymes have attracted considerable attention as a new type of promising artificial enzyme in recent years. Here, an oxidase-like cobalt–nitrogen–carbon (Co–N/C-900) nanozyme with well-regulated metal atom spatial distribution has been derived from Co–Zn bimetal zeolitic imidazolate framework precursors and used to develop a facile colorimetric sensing method for L-cysteine. With the aid of Co–N/C-900, the colorless 3,3′,5,5′-tetramethylbenzidine (TMB) was oxidized to blue oxidized TMB in the absence of H2O2. However, the oxidation was inhibited after the addition of L-cysteine, and the blue color faded to colorless. Thus, Co–N/C-900 exhibited quite good oxidase-like activity with high catalytic efficiency. Therefore, a facile and efficient colorimetric method to sensitively determine L-cysteine with a low detection limit of 33 nM (S/N = 3) has been developed. Furthermore, favorable selectivity and anti-interference ability towards the determination of L-cysteine based on this approach have also been achieved. It is believed that this colorimetric method for the detection of L-cysteine based on Co–N/C-900 will show potential applications in bioscience and bioengineering.
研究领域:
生物化学
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分析化学
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纳米生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2020
·Vol. 129
·期 2
·865-881
·
IF 1.52
Liu Minjie,Zhang Hao,Wang Junyan,Zhao Guoming,Liu Di
A Co–N–C catalyst was fabricated via pyrolysis–reduction process. Dehydrogenation/hydrogenation and base catalysis performances of the Co–N–C catalyst were investigated by using the reductive coupling of nitroarenes with alcohols and aldol condensation as probe reactions. Various characterizations were performed to explore effects of reduction and pyrolysis temperature on the structure/composition and basicity of the Co–N–C catalyst, and the relationship between structure-dehydrogenation/hydrogenation and base catalysis performance was discussed accordingly. Two different structures of Co–N–C catalyst (Co–N–C/C 3 N 4 and Co–N–C/CNT) were obtained in different pyrolysis temperature. Co–N–C-600 with C 3 N 4 exhibits very weak catalytic performance owe to its poor pore system and active phase. Dehydrogenation/hydrogenation behaviors of Co–N–C/CNT depend on the amount of Co–N, graphitic N in Co–N–C, while the basicity of Co–N–C is closely related to the content of N species, particularly pyrrolic N and pyridinic N. The appropriate pyrolysis temperature benefits the formation of active species, developed pore organization and strong basicity. And, the H 2 reduction improve dehydrogenation/hydrogenation activity of Co–N–C/CNT because reduction can destroy carbon coating layers to expose more Co–N species and promote the transformation of N species to graphitic N. Meanwhile, H 2 reduction increases the contents of graphitic N and reduces the content of pyrrolic N and pyridinic N, thus weakening catalyst basicity and consequently reducing base catalytic activity of Co–N–C/CNT.
研究领域:
化学
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2019
·
IF 4.888
Mantang Chen,Nan Wang,Lihua Zhu
Single-atom catalysts with a maximum atomic utilization are promising in wastewater treatment. Herein, a single-atom dispersed Co-N-C catalyst was prepared by a calcination-acid treatment method. The obtained Co-N-C was confirmed to possess excellent performances of both adsorption and catalytic ability of activating peroxymonosulfate (PMS). It was found that the adsorption performance was related to the surface area and pore volume and the removal of bisphenol A (BPA) was determined by the defect density of the catalyst. It was observed that a calcination temperature of 900 °C yielded the best Co-N-C catalyst named Co-N-C-900. All the added BPA (80 mg L −1 ) was completely degraded in 3 min by using 0.5 g L −1 Co-N-C-900 and 0.3 g L −1 PMS with a degradation rate constant ( k ) of as high as 2.81 min −1 . In this single-atom catalytic system, the main reactive species were confirmed to be singlet oxygen. A mechanism study suggested that the fast and efficient degradation of BPA was attributed to the synergistic effect between fast adsorption of mesoporous carbon and efficient catalysis of single-atom Co-N x complex.
研究领域:
环境科学
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材料科学
·
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）