Frontiers of Chemical Science and Engineering
·
2018
·Vol. 12
·期 3
·409-416
·
IF 2.643
Hao Meifeng,Xiao Mingshu,Qian Lihong,Miao Yuqing
A low-cost and high-activity catalyst for oxygen evolution reaction (OER) is the key to the water splitting technology for hydrogen generation. Here we report the use of three solvents, DMF, ethanol and glycol, in the solvothermal synthesis of three nano-catalysts, Co 3 (VO 4 ) 2 -I, Co 3 (VO 4 ) 2 -II, and Co 3 (VO 4 ) 2 -III, respectively. Transmission electron microscope shows Co 3 (VO 4 ) 2 -I, II, and III exist as ultrafine nanosheets, ultrathin nanofilms, and ultrafine nanosheet-comprised microspheres, respectively. These Co 3 (VO 4 ) 2 catalysts exhibit OER electrocatalysis, among which the Co 3 (VO 4 ) 2 -II shows the lowest onset overpotential of 310 mVand only requires a small overpotential of 330 mV to drive current density of 10 mA/cm 2 . Due to their high surface free energy, the ultrathin nanofilms of Co 3 (VO 4 ) 2 -II exhibits a good immobilization effect with the high electrocatalytic activity for OER.
研究领域:
材料科学
·
电化学
·
纳米科技
·
催化化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
·Vol. 45
·期 3
·1466-1476
·
IF 4.084
Yuelong Xu,Xiaoxi Dong,Junfeng Miao,Shasha Wang,Zhan Liu,Zuozhao Zhai,Lihui Zhang,Zhenfa Liu
Carbon nanomaterials that are electrochemically bifunctional and active in supercapacitor and hydrogen-evolution-reaction (HER) applications have attracted recent research attention. We have prepared porous carbon spheres - doped Ni, Co - alloys by using a hydrothermal method with melamine and pectin as precursors and with the addition of nickel nitrate and cobalt nitrate. The corresponding materials exhibit good electrochemical performance and excellent electrocatalytic activity for HER. The overpotential (OP) of the as-prepared materials can achieve 240 mV keeping a Tafel slope (TS) of 55 mV dec −1 at 10 mA cm −2 in an acid (0.5 M H 2 SO 4 ) solution. The corresponding samples maintain stability after 24 h and 5000 cycles in the chronovoltage and cyclic voltammetry methods, respectively. When the as-prepared materials are oxidized by 30% H 2 O 2 for 12 h, the corresponding as-prepared oxidation samples exhibit excellent electrochemical performance in a supercapacitor application. The specific capacitance (SC) of the as-obtained materials reaches 312 F g −1 at 1 A g −1 with decent rate capability and cyclic stability. This work provides new applications for bifunctional electrochemically active materials.
研究领域:
材料科学
·
电化学
·
纳米材料
·
能源存储
·
催化化学
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
·
2019
·Vol. 9
·期 21
·6037-6046
·
IF 5.726
Min Zhong,Jungang Wang,Congbiao Chen,Zhancheng Ma,Litao Jia,Bo Hou,Debao Li
Herein, the shell–core-structured SiC–Al2O3@Al composite consisting of an Al metal core and a SiC–Al2O3 hybrid shell was synthesized by a straightforward preparation method. Compared with Al2O3@Al composites, the SiC-modified samples possess a meso–macroporous structure, high pore volume, wide pore size, and a special surface where active and inert components coexist. The ratio of inert to active components on the composite surface could be modulated by controlling the amount of SiC nanoparticles (NPs). Upon the decoration of SiC NPs, the degree of reduction of cobalt oxides and the density of active sites (Co0) increased significantly. Moreover, the SiC-modified catalysts exhibited lower apparent activation energy (Ea) and higher intrinsic reaction rate (TOF) mainly due to the electron-rich properties of Co NPs in the modified samples. Accordingly, the cobalt-weight normalized FT activity (CTY) of the SiC-modified catalysts increased by a factor of about 1.6–2.0. Moreover, the catalyst modified by the SiC NPs showed lower selectivity towards light hydrocarbons (CH4 and C2–C4) but higher selectivity towards long-chain hydrocarbons (C5+). When the mSiC/mAl ratio was 15%, the CoAC-15 catalyst showed maximum density of active sites and highest TOF, leading to highest activity and C5+ selectivity (approximately 92%). The synergistic effect of the SiC–Al2O3 hybrid shell and the Al metal core was beneficial for the catalytic properties of the Co/SiC–Al2O3@Al catalysts. The binary SiC–Al2O3 nanostructure endowed the Co NPs with electron-rich characteristics to enhance the CO activation; moreover, the special surface where the active and inert components coexisted improved the reducibility of cobalt oxides, and the abundant porosity of the hybrid shell facilitated the transfer of reactants and products. In addition, the existence of the Al metal core improved heat transfer in the reaction.
研究领域:
材料科学
·
催化化学
·
能源化学
·
纳米技术
·
表面科学
✓ 已验证
DOI
高影响因子
ACS Applied Engineering Materials
·
2024
·
IF 0
Bin Qiao,Jing Zhang,Xuhui Li,Xingming Ning,Zhongwei An,Xinbing Chen,Yu Chen,Pei Chen
The rational design and control of active sites are essential for achieving a highly active and stable electrocatalyst. Herein, we report a bifunctional oxygen electrocatalyst, nanocrystals of CoF2-inserted carbon nanofibers, which was prepared by electrospinning and a subsequent fluorination process. Due to the large specific surface area and hierarchical porous structure, carbon nanofibers provide rapid mass transfer and expose more active sites for electrocatalytic oxygen reactions. The surface-oxidized CoF2 nanocrystals show high electroactivity for both the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) in alkaline solution, marked by up to 0.822 V of the ORR half-wave potential and as low as 370 mV of the OER overpotential. Benefiting from the excellent electrocatalysis activity, this material exhibits an excellent application prospect in rechargeable zinc-air batteries. As an air electrode catalyst, it can endow the zinc-air battery with a high specific capacity (871.2 mAh g–1), a large power density (124.30 mW cm–2), and excellent stability (120 h continuous charge/discharge), dramatically outperforming that of commercial Pt/C and RuO2 electrocatalysts. Density-functional theory (DFT) calculations indicate that surface oxygen atoms on CoF2 play a key role in enhancing the activity of Co atoms by p-d orbital hybridization. This work provides a perspective for designing bifunctional oxygen electrocatalysts urgently needed by rechargeable zinc-air batteries.
研究领域:
材料科学
·
电化学
·
能源技术
✓ 已验证
DOI
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Guansheng Ma,Yuefeng Yan,Yuming Feng,Kaili Zhang,Boshi Gao,Jun Weng,Guangyu Qin,Seeram Ramakrishna,Xiaoxiao Huang
To cope with different environments of application, electromagnetic wave absorption (EWA) materials with multifunctionality have attracted a wide range of interests. And excessive heavy metal ions in aqueous solutions seriously affect people’s health and pose a major challenge to environmental safety. In this study, carbon microtube/carbon nanotube (CMT/CNT) composites were fabricated via carbonization and chemical vapor deposition (CVD) methods. The CNT wrapped with cobalt nanoparticles were grown in situ on the CMT which derived from kapok fiber. By varying the concentration of cobalt precursors, the EWA and Cu(II) adsorption performances of CMT/CNT can be efficiently tuned. Optimizing the cobalt content to 2 wt% resulted in a minimum reflection loss ( RL ) of −66.14 dB at a matching thickness of 1.91 mm, with an effective absorption bandwidth (EAB) of 5.35 GHz. The adsorption capacity of Cu(II) by the CMT/CNT composite can reach 102.01 mg/g when the initial Cu(II) concentration is 500 mg/L. This research not only shows great promise for applications in the field of EWA materials but also holds significant potential for heavy metal ion removal and as a catalyst carrier, among other areas.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Lixin Sun,Yunong Qin,Lishan Fu,Yutong Di,Kaidi Hu,Hailong Li,Ling Li,Wenming Zhang
Secondary zinc-air batteries (ZABs) with a free-standing and flexible air electrode integrated with distinguished bifunctional oxygen electrocatalysts are crucial for achieving better performance. Herein, benefitting from the rational design and simple synthesis, a highly controlled design can be achieved for the first showing of the synthesis of Co 3 O 4 /Fe 2 O 3 NAs@CNFs with a unique hierarchical nanostructure , consisting of randomly distributed zero-dimensional (0D) Co 3 O 4 /Fe 2 O 3 nanoparticles embedded in two-dimensional (2D) MOF derived nitrogen-doped mesoporous carbon flake nanoarrays grown on three-dimensional (3D) microporous network with interconnected conductive one-dimensional (1D) carbon nanofibers from carbonized electrospinning polymer nanofiber film (PMNFs). Under the synergy of 3D hierarchical porous nanostructure and abundant accessible active sites, Co 3 O 4 /Fe 2 O 3 NAs@CNFs is endowed with excellent bifunctional electrocatalytic activities like those of commercial Pt/C and RuO 2 , respectively. Rechargeable aqueous ZABs based on Co 3 O 4 /Fe 2 O 3 NAs@CNFs as air electrodes outperform their counterparts based on Pt/C and RuO 2 loaded carbon nanofibers (CNFs) as air electrodes, with a maximum power density of 246 mW cm −2 and excellent cycling stability with no increased polarization even after 40 h. And the assembled flexible solid-state ZABs with Co 3 O 4 /Fe 2 O 3 NAs@CNFs also display superior performance and bendability.
研究领域:
材料科学
·
电化学
·
能源存储与转换
✓ 已验证
DOI
高影响因子
Materials Today Energy
·
2017
·
IF 0
Yan Cui,Rui Zhang,Jian Zhang,Zikai Wang,Hongtao Xue,Weiwei Mao,Wei Huang
The development of highly active and earth-abundant electrocatalysts for the hydrogen evolution reaction (HER) from water holds great promise for clean energy storage and conversion technologies. Pyrite phase transition metal disulfides based electrocatalysts have attracted much attention because of their activity and earth-abundance. In this work we report on the synthesis of in-situ growing quaternary Co 0.8 Ni 0.1 Fe 0.1 S 2 nanoparticles decorating on the reduced graphene oxide (CNFS@rGO) as hybrid Pt-free HER catalyst with high-activity as well as durability. Specifically, the additional active sites can attribute to the incorporation of the Ni and Fe, moreover, the enhancement of anti-aggregation and electron transporter efficiently from rGO which is visually verified by the result of electrochemically active area. As a result, the nanohybrid electrocatalysts possess high HER properties with the need of overpotential of only 138 mV to drive 10 mA cm −2 , an small Tafel slope of 49 mV dec −1 , and superior long-term continuous durability in 0.5 M H 2 SO 4 (over 33 h). This study offers us a pathway to design and fabrication of multicomponent low-cost metal disulfides based electrocatalysts.
研究领域:
材料科学
·
能源化学
✓ 已验证
DOI
Journal of Energy Chemistry
·
2020
·
IF 7.216
Wenlei Guo,Wenping Si,Tao Zhang,Yonghuan Han,Lei Wang,Ziyue Zhou,Pengyi Lu,Feng Hou,Ji Liang
The rapid development of portable and wearable electronics has called for novel flexible electrodes with superior performance. The development of flexible electrode materials with excellent mechanical and electrochemical properties has become one of the key factors for this goal. Here, a Ni x Co y -silicate@CNTs film is developed as a flexible anode for lithium ion batteries (LIBs). On this film, Ni x Co y -silicate nanosheets are firmly and intimately anchored on the surface of CNTs , which have a 3D network structure and link the adjacent nanosheets together. Benefitted from this, the composite film is not only sufficient to withstand various deformations due to its excellent flexibility but also has excellent electrochemical properties, in terms of high reversible capacity of 1047 mAh g −1 at 0.1 A g −1 as well as a high rate and cycling performance (capacity retention up to 78.13% after 140 cycles). The pouch-type full flexible LIB using this material can stably operate under various bending conditions, showing the great potential of this 3D Ni x Co y -silicate@CNTs film for flexible energy storage devices with high durability.
研究领域:
材料科学
·
能源存储
·
纳米技术
✓ 已验证
DOI
高影响因子
CARBON
·
2020
·
IF 8.821
Yujin Li,Cuimeng Song,Jinchao Chen,Xueni Shang,Jinping Chen,Yun Li,Min Huang,Fanbin Meng
Developing low-cost and highly efficient electrochemical materials toward supercapacitor applications is crucial for energy conversion systems. In the present work, dual S, N-doped activated CoFe 2 O 4 @CNTs was successfully synthesized using carbamide and sodium thiosulfate as N and S precursors and CNTs as a substrate via a convenient two-step hydrothermal activation procedure, which presents good performance for supercapacitor. The characterization results indicate that activity S and N atoms can be successfully doped into the framework of CoFe 2 O 4 @CNTs with little impact on the inner morphology and structure. However, the electrode material of N 2 S 1 –CoFe 2 O 4 @CNTs exhibits a superior electrochemical performance with 1053.60 F g −1 at 1 A g −1 in KOH electrolyte due to synergistic effects between spinel-type metal oxides , heteroatoms and sp 2 lattice of graphitic carbon. In addition to high energy and power densities, the capacitance retention of charging-discharging reaches 93.15% at a current density of 30 A g −1 after 5000 cycles, exhibiting an outstanding cycle stability and potential lifetime in an alkaline electrolyte .
研究领域:
材料科学
·
能源转换与存储
✓ 已验证
DOI
高影响因子
ChemCatChem
·
2024
·
IF 3.8
Chao Wang,Chunqun Qin,Mingzheng Liao,Yanping Du,Jiming Gao,Yanbing Wu
High-entropy oxides (HEOs), known for their excellent thermodynamic stability due to their high-entropy effect. In this study, high-entropy (NixAlCoCrMn)3O4 oxides of spinel structure were synthesized by sol-gel method. This HEO has a self-reconfiguration properties in the reaction, and its internal Ni and Co ions exsolve to form a uniformly dispersed NiCot alloy on the surface. The increase of Ni content promotes the exsolution of Ni and Co ions from the interior of the spinel. The high-entropy with a large number of oxygen vacancies not only possesses a stable structure to limit the migration of NiCo alloys, but also enhances the hydrogen overflow. In the CO methanation reaction, it has 99% CO conversion with 87% methane selectivity within 400 oC, and it is stable in the long-term test. This work provides a new idea for exploring the use of high-entropy materials to improve thermal catalytic activity and stability.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
·
IF 4.084
Li Gong,Kai Lan,Xiang Wang,Xiaokang Huang,Pengbo Jiang,Kaizhi Wang,Ming Yang,Lei Ma,Rong Li
Exploration of noble-metal-free, highly-efficient and durable catalysts for Hydrogen evolution reaction (HER) remains a challenge. In this work, the development of carbon-coated cobalt-molybdenum-phosphide nanosheets supported on carbon cloth (Co-Mo-P@C) is successfully demonstrated. To obtain a better electrocatalystic performance, the different amount of glucose was added into the reaction system during hydrothermal process. Benefiting from the 2D structure, high electrical conductivity and sufficient active sites, the Co-Mo-P@C contained 0.5 mmol glucose exhibits relatively good catalytic activity for HER with low over poentials at −96 mV and −162 mV @ 10 mA cm −2 in acidic and alkaline medias respectively and the Tafel slope of 52.9 mV dec −1 and 34.3 mV dec −1 . Additionally, the catalyst also shows good durability in the both electrolytes.
研究领域:
材料科学
·
能源化学
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2020
·
IF 0
Yixiang Pan,Xiaoyan Wang,Jianguo Lu,Qing Yan,Weiyong Yuan,Chang Ming Li
Metal–organic complex (MOC) multilayers are, for the first time, conformally constructed on Ni foam (NF) via a three-component sequential layer-by-layer (LbL) self-assembly approach and converted to three-dimensional (3-D) NF-supported interconnected CoO nanoparticles (NPs)/N-doped carbon nanohybrid multilayers via calcination. The obtained nanoarchitecture delivers an overpotential of 318 mV to achieve 10 mA cm–2 and a Tafel slope of 46.1 mV dec–1. This activity is superior to most reported oxygen evolution reaction (OER) catalysts, and even much better than those of Ir- and Ru-based ones measured under the same conditions (0.1 M KOH). Additionally, this electrode undergoes negligible potential and current change after 19.8 h chronopotentiometric measurement and 300 cyclic voltammetry cycles. The outstanding catalytic performance is mainly attributed to the ultrasmall and high-density CoO NPs embedded in N-doped carbon uniformly assembled on the 3-D substrate significantly increasing electrochemically accessible active sites and durability and the N-doped carbon greatly promoting intrinsic activity of CoO. This work not only creates 3-D highly tunable networked nanostructured electrodes with excellent durability for high-efficiency electrocatalysis but also develops a facile, economical, and extremely versatile strategy to controllably self-assemble conformal MOC-based multilayers with multifunctionality and superior performance on essentially any substrate at the molecular level for broad applications.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
危险品化学品经营许可证（带存储）