Sustainable Energy & Fuels
·
2019
·Vol. 4
·期 4
·1654-1664
·
IF 4.912
Caiyun Wu,Yunmei Du,Yunlei Fu,Di Feng,Hui Li,Zhenyu Xiao,Yanru Liu,Yu Yang,Lei Wang
In this study, a composite of Mo, Co co-doped NiS bulks grown on an Ni foam (Mo,Co-NiS/NF) was synthesized as a bi-functional electrocatalyst for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) using a simple method. The existence of ZIF-67 and Mo ensure the even distribution of Co and Mo elements and the formation of N doped carbon layer in Mo, Co-NiS/NF. Mo, Co co-doping and NF support greatly improved the electrocatalytic performance of NiS bulks, because metal element doping could improve the intrinsic activity and electrical conductivity. Moreover, the Ni foam could act as a substrate to avoid aggregation and provide nickel source to form the bimetallic sulfide. The product Mo,Co-NiS/NF-400 showed outstanding electrochemical properties, with ultralow overpotential (92 mV vs. RHE) for HER and ultralow overpotential (117.2 mV vs. RHE) for OER to achieve 10 mA cm−2, as well as the ultralow cell voltage (1.36 V) to achieve 20 mA cm−2 for overall water splitting. This study provides an available method to promote the electrocatalytic activity of the traditional monometallic sulfides for overall water splitting.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Cheng Lv,Jiayan Huang,Yuang QI,Qingjie He,Yazhou Wang,Cuili Xiang,Yongjin Zou,Fen Xu,Lixian Sun
MgH₂ is one of the most promising materials for solid hydrogen storage and is environmentally friendly primarily owing to its high mass hydrogen storage density (7.6 %). However, the application and development of MgH₂ are limited by its sluggish kinetics, requiring high processing temperatures. In this study, we prepared Ni/Co-co-doped Ti 2 VC 2 bimetallic MXene nanosheets via etching and the hydrothermal method. These nanosheets were then doped into MgH₂, resulting in drastically improved hydrogen storage properties. The MgH₂-based composite hydrogen storage materials doped with 10 wt% Ni/Co–Ti 2 VC₂ (TVCNC) commenced hydrogen emission from 183 °C and could emit 6.65 wt% hydrogen at 300 °C. During the rehydrogenation test, the composites could still absorb hydrogen at 5.0 wt% within a 10 min window at a hydrogen pressure of 20 bar at 125 °C. Moreover, the hydrogen absorption and emission kinetics of the doped MgH₂ were considerably improved. This improvement could be ascribed to the significantly increased specific surface area of the MXene nanosheets after etching, which increased the number of active sites on the surface to accelerate the reaction, thereby accelerating hydrogen adsorption and emission. In addition, the migration of electrons between the multivalent Ti ions as well as between Ni and Co helped accelerate bond cleavage between magnesium and hydrogen, thereby enhancing the kinetic properties. Ni/Co co-doping produced Mg 2 Ni alloys with magnesium via hydrogen adsorption and emission, thus improving the reaction kinetics of the composites.
研究领域:
材料科学
·
能源储存
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL SCIENCES
·
2022
·Vol. 134
·期 2
·1-11
·
IF 2.15
Yu Miao,Ji Shuai,Li Zhifang,Song Kun,Li Yueyu,Yang Jian,Yang Changlong
A simple ion-exchange method is used to prepare Mn and Co-supported TNU-9 denitration catalyst for NH 3 -SCR. The denitration activity and H 2 O/SO 2 resistance performance of the catalyst are systematically studied. The denitration activity test exhibits that the NO x removal rate of Mn-Co/TNU-9 is higher than that of Mn/TNU-9 and Co/TNU-9, the NO x removal rate is greater than 90% and the N 2 selectivity is greater than 99% in the range of 150 ~ 450 °C. It is because the redox cycle of Mn 4+ + Co 2+ ↔ Mn 3+ + Co 3+ improves the redox performance of the catalyst, which is conducive to the conduction of electrons, and then accelerates the oxidation of NO to NO 2 to produce a "fast SCR" reaction, and finally optimizes the overall SCR performance. Furthermore, the change is not significant for the catalytic activity over Mn-Co/TNU-9 in the presence of water. However, the sulfur resistance is poor at low temperatures due to the presence of ammonium bisulfate. It also has excellent catalytic stability. Therefore, supported TNU-9 catalysts will have a good development prospect in denitrification. Graphical abstract Mn-Co co-doped TNU-9 catalyst was successfully synthesized by simple ion exchange method and applied in the NH 3 -SCR. The results show that Mn-Co/TNU-9 catalyst has an excellent wide activity window in a wide temperature range of 150-450°C (NO x conversion over 90%), which is because Mn+Co 2+ ↔Mn+Co improves the redox performance and facilitates the electron transfer, which further accelerates the oxidation of NO into NO 2 that could result in the “Fast SCR” reaction. The synergistic effect between Mn and Co bimetallic can also improve activity. Moreover, Mn-Co/TNU-9 has very good catalytic stability.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2021
·Vol. 51
·期 6
·2219-2225
·
IF 4.39
Chen Chen,Jiamei Zhao,Dong Guo,Keyu Duan,Yongqiang Wang,Xiaowen Lun,Conglu Zhang
CaTiO3 is considered to be one of the most promising catalysts for the degradation of organic pollutants, but its application is limited by the wide band gap and low catalytic activity. Element doping is an effective strategy to solve these problems. Herein, a novel CaTiO3 co-doped with Ag and Co (Ca1−xAgxTi1−yCoyO3) was synthesized by combining co-precipitation and the microwave hydrothermal method for the first time. The crystal structure, microstructure and light absorption of the material were systematically investigated. The results showed that Ca1−xAgxTi1−yCoyO3 had higher light absorption than pure CaTiO3, and the band gap was reduced to 2.78 eV. First-principles calculations indicated that Ag–Ca and Co–Ti tended to form donor–acceptor defect pairs in the doping process. These defect states not only enhanced the adsorption properties, but also could be used as carrier traps to optimize the dielectric properties of CaTiO3. In the photoelectrocatalytic system, with 0.01 g of catalyst, 98% of methylene blue in 100 mL solution (10 mg L−1) was degraded in 150 min. In addition, Ca1−xAgxTi1−yCoyO3 showed strong stability and excellent recyclability. The double ion co-doping technology will provide an effective strategy for improving the catalytic activity of traditional wide-band gap semiconductors.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Chang Miao,Meiling Ma,Yingrui Sui,Yue Cui,Zhanwu Wang,Lili Yang,Fengyou Wang,Xiaoyan Liu,Bin Yao
Environmentally benign and earth-abundant constituent’s kieserite Cu 2 ZnSn (S, Se) 4 (Cotises) is considered as a hopeful photovoltaic material. Unfortunately, the severe tail state caused by various harmful deep defects in CZTSSe absorber prevents further development of its device efficiency. Here, we report firstly that the Co was incorporated into CZTSSe films to form the Cu 2 Co x Zn 1-x Sn (S, Se) 4 (CCZTSSe) films using a two-step annealing and solution-processing technique method. Through optimized the Co/(Co+Zn) ratio, the CCZTSSe film has excellent good surface morphology and single-phase composition. Appropriate amount of Co elements replacing Zn elements in CZTSSe films can effectively reduce the degree of Cu-Zn disorder, thus inhibiting [2Cu Zn +Sn Zn ] defect clusters and Cu Zn defects. The detrimental deep defects located in the film were effectively passivated to reduce electrostatic potential fluctuations, resulting in relief of the trailing state. Therefore, a champion device having an efficiency of 7.50 % with a fill factor (FF) of 61.00 % was achieved from CCZTSSe with 3 % Co content. This work provides new insights into the impacts of Co doping in CZTSSe by a solution processed method and offers a deeper comprehension of the origin of the efficiency enhancement of CCZTSSe devices.
研究领域:
材料科学
·
能源技术
·
半导体物理
✓ 已验证
DOI
高影响因子
ACS Applied Energy Materials
·
2025
·
IF 5.5
Ruiqing Zhang,Guanyu Li,Shiyi Chen,Wenguo Xiang
The successful commercialization of concentrated solar power (CSP) plants necessitates the development of efficient energy storage systems to ensure the on-demand power generation during solar transients. In recent years, the redox cycling of doped CaMnO3−δ has emerged as a promising approach for thermochemical energy storage (TCES) in CSP applications. This study aims to enhance the thermochemical energy storage capability of CaMnO3−δ by co-doping with Sr and Co at the A- and B-sites, respectively, forming (SrxCa1–x)(CoxMn1–x)O3–δ. Two doping levels (x = 0.05 and 0.10) were investigated. XRD and SEM–EDS analyses confirmed that Sr and Co were homogeneously incorporated into the perovskite lattice, yielding porous microstructures in both compositions. Notably, evaluation of the thermochemical energy storage (TCES) densities of these codoped perovskites under diverse thermal energy storage conditions revealed that although the two materials exhibited different heat storage processes, comparable TCES densities were ultimately achieved. In particular, under favorable thermochemical energy storage conditions (1100 °C, pO2 = 10–5 atm), the thermochemical energy storage densities of Sr0.05Ca0.95Co0.05Mn0.95O3–δ and Sr0.10Ca0.90Co0.10Mn0.90O3–δ achieved 459 kJ/kgABO3 and 470 kJ/kgABO3, respectively. However, in the subsequent redox cycle tests, Sr0.10Ca0.90Co0.10Mn0.90O3–δ demonstrated a stronger reoxidation capability compared to Sr0.05Ca0.95Co0.05Mn0.95O3–δ. Compared to the undoped material, both co-doped samples exhibited significant improvements in the TCES density and thermal stability. Moreover, the isothermal redox reaction rate measurements and the analysis revealed the rapid redox reaction rate in both materials, providing valuable insights for the development of advanced perovskite-based thermochemical energy storage systems.
研究领域:
材料科学
·
能源存储技术
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Menglin Wu,Jiupai Ni,Chengsheng Ni
In situ exsolution of nanoparticles has been reported to be an efficient path to optimize CO2 electrolysis performance. Herein, a Ce/Co co-doped SrFeO3-δ (SF) can achieve the co-exsolution of CeO2 and Co–Fe alloy in 5% H2 at 800 °C. A small amount (<10%) of Ce-doped SF cannot stabilize the perovskite structure in a reducing atmosphere. Sr0.9Ce0.1Fe0.9Co0.1O3 (10Ce10CoF) and Sr0.95Ce0.05Fe0.9Co0.1O3 (5Ce10CoF) as symmetric electrodes of solid oxide electrolysis cells showed an excellent electrolysis performance at 800 °C for CO2 electrolysis. The current densities of the cells with 5Ce10CoF and 10Ce10CoF reached 0.98 and 1.30 A cm–2 under a bias of 1.3 V after a 48 h durability test for CO2 electrolysis, respectively, and the performance difference, however, may be due to CeO2 being more easily exsolved from the 10Ce10CoF lattice. We also investigated the role of the exsolved CeO2 and oxygen vacancy (VO) in determining the CO2 electrolysis performance via theoretical calculation. In this work, we designed a novel strategy to achieve the exsolution of CeO2 and Co–Fe alloy via reduction treatment and showed an outstanding CO2 electrolysis performance.
研究领域:
材料科学
·
化学工程
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
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