JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Changming Zhang,Zhihao Liu,Yongjin Zou,Fen Xu,Lixian Sun,Zhicong Hu,Sensen Yu,Cuili Xiang
Spinel-type materials are attracting great attention as potential electrocatalysts for the hydrogen- and oxygen-evolution reactions. However, their inherent catalytic activities are not on par with those of precious-metal catalysts, and their poor stabilities continue to constrain their rapid development. In this study, we fabricated Zr-CuCo 2 S 4 nanowires and Co(OH) 2 nanosheet–nanowires using electrochemical methods, resulting in lattice defects, sulfur vacancies, and more exposed active sites that catalyze the hydrogen- and oxygen-evolution reactions. DFT calculations revealed that sulfur vacancies enhance intrinsic activity, while Zr doping reduces the energy barrier for H*–OH* adsorption, promotes the formation of additional sulfur vacancies, and modulates active-site Cu/Co valence states, which greatly enhances water-dissociation and H*-adsorption kinetics. Consequently, Zr-CuCo 2 S 4 /Co(OH) 2 requires low overpotentials of 88 and 208 mV, respectively, to support highly stable alkaline hydrogen- and oxygen-evolution reactions at 10 mA cm −2 . This study provides a rational strategy for designing low-cost spinels for green and clean energy.
研究领域:
材料科学
·
电化学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 51
·33056-33063
·
IF 4.036
Bo Huang,Zhihua Zhao,Pu Chen,Baocang Zhou,Zhuo Chen,Yu Fu,Hongyu Zhu,Chen Chen,Shuaiwen Zhang,Anbiao Wang,Pu Shi,Xiaoqing Shen
Ammonia (NH3) is a common air pollutant and is a biomarker for kidney disease. Therefore, the preparation of ammonia gas sensors with high sensitivity, good selectivity and low operating temperature is of great importance for health protection. Using the in situ electrostatic self-assembly approach, a chemoresistive gas sensor based on Co(OH)2/Ti3C2Tx hybrid material was created in this study. The prepared samples were characterized by XRD, XPS, TEM, BET and other testing methods for structure, surface topography and elements. These samples were fabricated into sensors, and the gas sensing properties of the materials were investigated under different test conditions. The results show that the gas response value of the C/M-2 sensor is up to about 14.7%/100 ppm, which is three times the response value of the sensor made of pure MXene to NH3. In addition, the Co(OH)2/Ti3C2Tx hybrid sensors exhibit excellent repeatability, high sensitivity under low concentration (less than 5 ppm), fast response/recovery time (29 s/49 s) and long-time stability, which indicates their promising utility in the IoT field.
研究领域:
材料科学
·
传感技术
·
健康监测
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysts
·
2025
·Vol. 15
·期 3
·219
·
IF 4
Xuan Han,Chao Guo,Hui Wang,Weijuan Xu,Qinlian Liu,Qingshan Zhao,Mingbo Wu
Hydrogen production from water electrolysis offers a highly promising and sustainable route to solve the energy crisis. However, it is severely limited by the sluggish kinetics of the oxygen evolution reaction (OER) occurring on the anode. Herein, employing carbon dots functionalized with benzene sulfonate groups (BS-CDs) as a distinctive inductor, a Co(OH)2catalyst featuring abundant defects was synthesized for an enhanced OER. The highly hydrophilic nature of BS-CDs exerts a significant interfacial induction effect on the growth dynamics of Co(OH)2, fostering the formation of elevated crystal defects and a substantial quantity of oxygen vacancies. The resulting BS-CDs/Co(OH)2catalyst requires an overpotential of only 340 mV to achieve a current density of 10 mA cm−2in alkaline media, demonstrating markedly improved OER activity compared to pristine Co(OH)2and N-CDs/Co(OH)2induced by amine-modified CDs. Furthermore, the structural integrity of the catalyst is maintained, with a current retention rate of 92% observed following a 20 h stability assessment. This work provides a novel approach for developing cost-effective transition metal catalysts that exhibit exceptional catalytic efficiency and excellent stability for the OER.
研究领域:
材料科学
·
催化化学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2015
·Vol. 78
·期 2
·293-298
·
IF 1.532
Cui Hongtao,Ma Wenle,Wang Li,Xue Junying
Abstract
In this work, α-Co(OH) 2 monolayer nanosheets were prepared by an intercalation agent-free route utilizing a precipitation reaction between epoxide and aqueous complexes of cobalt ions ([Co(H 2 O) 6 ] 2+ ). The protonation and the following ring-opening reaction of epoxide promoted the hydrolysis of [Co(H 2 O) 6 ] 2+ , leading to the formation of α-Co(OH) 2 nanosheets. The obtained nanosheets were then exfoliated to monolayer nanosheets in formamide under ultrasonic vibration. A possible exfoliation mechanism is proposed for the exfoliating process of α-Co(OH) 2 nanosheets. The water molecules incorporated in the layered structure of α-Co(OH) 2 are considered to be the key medium for the layer exfoliation. It seems that the water molecules coordinated with the cobalt ions weakened the interlayer interaction. Therefore, the extraction of water molecules by formamide readily broke the interlayer connection in α-Co(OH) 2 , resulting in the exfoliation of nanosheets. Graphical Abstract α-Co(OH) 2 monolayer nanosheets were prepared by an intercalation agent-free route utilizing a precipitation reaction between epoxide and aqueous complexes of cobalt ions ([Co(H 2 O) 6 ] 2+ ).
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2023
·
IF 6.6
Chunyan Fan,Zehao Zang,Xiang Li,Junfang Zhang,Ping Yang,Lanlan Li,Xiaofei Yu,Xiaojing Yang,Zunming Lu,Xinghua Zhang
Transition metal hydroxides have superior oxygen evolution reaction (OER) activity but poor hydrogen evolution reaction (HER) performance, which greatly limits the water splitting for hydrogen production. Herein, copper modification of sulfur doped Co(OH) 2 hybrid catalyst (Cu@S-Co(OH) 2 ) was prepared by one-step of electrodeposition method which can serve as efficient hydrogen evolution reaction catalyst. In the presence of sulfur and copper, Cu@S-Co(OH) 2 hybrid catalyst exhibits the best catalytic activity, showing ultralow overpotential of 42 mV at a current density of 10 mA cm −2 . Compared with Co(OH) 2 , the overpotential is improved by nearly 100 mV as well as enhanced stability. In addition, the active site poison experiments proved that the active center is cobalt metal. Combined with the adsorption strength of the catalyst for OH and H species, it is considered that both S and Cu can enhance the adsorption of OH for Co(OH) 2 , while S is contributed to the adsorption of H, and Cu can promote the desorption of H. This work provides a facile method and new insight to enhance the HER activity for transitional metal hydroxides via metal and non-metallic elements co-modulation.
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
DALTON TRANSACTIONS
·
2022
·Vol. 51
·期 22
·8832-8839
·
IF 4.569
Yihao Gao,Jie Bai,Tianning Zhou,Yaqiong Gong
In recent years, Co-based metal–organic frameworks (Co-MOFs) have received significant research interest because of their large specific surface area, high porosity, tunable structure and topological flexibility. However, their comparatively weak electrical conductivity and inferior stability drastically restrict the application of Co-MOFs in the synthesis of electrocatalysts. In this study, ZIF-67 was grown on nickel foam by a room temperature soaking method, and then Ir–Co(OH)2@ZIF-67/NF was assembled by a hydrothermal method. The prepared Ir–Co(OH)2@ZIF-67/NF nanosheets exhibit remarkable conductivity, larger electrochemical active surface area and wider electron transport channels. Only ultralow overpotentials of 198 mV, 263 mV, and 300 mV were needed for Ir–Co(OH)2@ZIF-67/NF to reach the current densities of 10 mA cm−2, 50 mA cm−2, 100 mA cm−2, meanwhile, no obvious degradation of the current density at 10 mA cm−2 was observed for about 16 h. This work may provide a promising strategy for developing high-performance MOF-derived materials as electrocatalysts for the OER under alkaline conditions.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 10
·13941-13947
·
IF 2.478
Liu Ying,Cao Bo,Zhang Xu,Luo Rong,Luo Chunhua,Lin Hechun,Peng Hui
Layered Co(OH) 2 has been regarded as a potential candidate for pseudocapacitor electrode material, but it is limited by its poor conductivity and low surface area. Herein, carbonated multi-walled carbon nanotubes (MWCNTs-COOH) were used to improve the conductivity of α-Co(OH) 2 nanocomposites. α-Co(OH) 2 nanoflowers were successfully grown and tangled with MWCNTs-COOH to form a randomly oriented network structure mediated by ammonia using water-methanol as co-solvent at room temperature. The capacitance performances of the obtained α-Co(OH) 2 @MWCNT-COOH composites were investigated to find that MWCNT-COOH improved the specific capacitance efficiently. Especially, in the presence of 20% in mole of MWCNT-COOH, the composite gave rise to the high specific capacitance of 1027 F/g at the current density of 2 A/g with good cycle stability, whose specific capacitance remained 78% of its original even after 5000 cycles at 30 A/g current. The large surface area and strengthening the conductivity of the composites lead to the improvement of efficiency in charge/discharge process.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
Small
·
2023
·Vol. 19
·期 20
·2207569
·
IF 13.3
Yakun Tian,Ming Wen,Aijian Huang,Qingsheng Wu,Zhiguo Wang,Quanjing Zhu,Tao Zhou,Yongqing Fu
High stability and efficiency of electrocatalysts are crucial for hydrogen evolution reaction (HER) toward water splitting in an alkaline media. Herein, a novel nano-Pt/Nb-doped Co(OH) 2 (Pt/Nb Co(OH) 2 ) nanosheet is designed and synthesized using water-bath treatment and solvothermal reduction approaches. With nano-Pt uniformly anchored onto Nb Co(OH) 2 nanosheet, the synthesized Pt/Nb Co(OH) 2 shows outstanding electrocatalytic performances for alkaline HER, achieving a high stability for at least 33 h, a high mass activity of 0.65 mA µg −1 Pt, and a good catalytic activity with a low overpotential of 112 mV at 10 mA cm −2 . Both experimental and theoretical results prove that Nb-doping significantly optimizes the hydrogen adsorption free energy to accelerate the Heyrovsky step for HER, and boosts the adsorption of H 2 O, which further enhances the water activation. This study provides a new design methodology for the Nb-doped electrocatalysts in an alkaline HER field by facile and green way.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2020
·Vol. 22
·期 2
·1-12
·
IF 2.132
Sun Xueying,Li Siqi,Liu Rongmei,Sun Xiulun,Liu Xinjie,Li Anran,Li Wen
In this work, we designed a simple hydrothermal synthetic method for a ZnCo-PBA@α-Co(OH) 2 nanosphere@nanosheet material with good electrochemical properties. The obtained material had a specific capacitance of 423.92 F g −1 at 1 A g −1 and a cycling retention ratio of 78.48% after 1000 cycles at 5 A g −1 . A hybrid supercapacitor device (ZnCo-PBA@α-Co(OH) 2 //AC) assembled with activated carbon as the negative electrode had a specific capacitance of 122.4 F g −1 at 1 A g −1 , a cycling retention rate of 73.53% after 5000 cycles at 5 A g −1 , and a very high energy density of 49.13 Wh kg −1 at power density of 1734.0 W kg −1 . The significantly improved electrochemical performance of the ZnCo-PBA@α-Co(OH) 2 nanocomposites can be attributed to the positive synergistic effects of the porous structure of the PBA material and the large specific surface area of the α-Co(OH) 2 nanosheets, on the ion permeability and number of active sites in the reinforcing material; thus, this composite is a potential material for use in future energy storage systems.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Shuaipeng Wang,Li Xu,Weixin Lu
Non-noble metal catalysts with high-performance are intensively exploited toward water electrolysis. Herein, we fabricate a novel Ni 3 S 2 @Co(OH) 2 heterostructure with a tentative method combining hydrothermal method with electrodeposition, in which the Ni 3 S 2 nanosheets are evenly integrated with Co(OH) 2 nanoparticles. Electrochemical tests reveal preeminent catalytic activities and durability on this heterostructure for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). It presents high catalytic activities of 110 and 257 mV at 10 mA cm −2 for HER and OER, respectively, in 1.0 M KOH solution. Moreover this bifunctional electrode requires only 1.61 V to reach 10 mA cm −2 and shows excellent durability when assembled as an electrolyzer, superior than that of Pt-C||IrO 2 . The promoted activities are benefited from the interfacial cooperation and synergistic effect between Ni 3 S 2 and Co(OH) 2 , because of which the charge-transfer ability is enhanced and surface reactivity is of furtherance. This work is of very profound significance on electrocatalysts for water splitting, specific performances: (1) This heterostructure is synthesized based on interface engineering. (2) The promoted performance is due to the synergistic effect of two onefold-components. (3) The catalysis activities for HER and OER can synchronously reach ideal states when it is used as bifunctional catalyst.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2024
·
IF 10.7
Yanpei Xu,Haoyu Wu,Meng Sun,Hongyu Song,Chuxiao Sun,Fudong Jia,Qi Wang
In the detection of biomolecules, surface plasmon resonance (SPR) sensors require high sensitivity. In this study, we propose a sensitivity-enhanced functionalized plasmonic interface based on Ag–TiO 2 –Co(OH) 2 nanosheets structure. Compared to unmodified SPR sensors, the sensitivity of the sensor decorated with TiO 2 and Co(OH) 2 nanosheets is increased by 130.84%, reaching 5764.27 nm/RIU. This enhancement is attributed to the high refractive index of the coating, as well as the high specific surface area and abundant active sites provided by the synthesized Co(OH) 2 nanosheets with a multi-grooved structure. Additionally, employing a double-antibody sandwich method, the antibody-functionalized plasmonic interface enables specific detection of human serum albumin (HSA). The linear response of this sensor was in the wide range of 0.4–150 μM, and the LOD reached 154.89 nM(K D is approximately 1.73 × 10 −6 M). This novel SPR sensor offers a new strategy for biochemical sensing and provides a highly sensitive platform for immunoassays.
研究领域:
生物传感器
·
纳米材料
·
医学检测
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2020
·
IF 4.939
Li-Wen Jiang,Yuan Huang,Bing-Bing Chen,Jian-Qiu Zhou,Hong Liu,Jian-Jun Wang
Hydrogen production via alkaline water electrolysis is of significant interest. However, the additional water dissociation step makes the Volmer step a relatively more sluggish kinetics and consequently leads to a slower reaction rate than that in acidic solution. Herein, we demonstrate an effective strategy that Co(OH) 2 can promote the Volmer process by accelerating water dissociation and enhance the electrocatalytic performance of CoP toward alkaline hydrogen evolution reaction . The Co(OH) 2 nanoplates are electrochemically induced in-situ generated to form a nanotree-like structure with porous CoP nanowires , endowing the hybrid electrocatalyst with superior charge transportation, more exposed active sites, and enhanced reaction kinetics. This strategy may be extended to other phosphides and chalcogenides and provide insight into the design and fabrication of efficient alkaline HER catalysts.
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）