JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2018
·
IF 5.091
Ying Liu,Fei Yang,Wei Qin,Guowei Yang
The Co 2 P@NiCo 2 O 4 bi-functional electrocatalyst was fabricated for hydrogen evolution reaction and oxygen evolution reaction in acidic, neutral and alkaline media. The Co 2 P@NiCo 2 O 4 in alkaline media exhibites an extremely low overpotential of 170 mV in oxygen evolution to achieve a current density of 10 mA cm −2 and produces stable water splitting nearly 30 h. The anchored-Co 2 P can enhance the electrochemical performance of pristine NiCo 2 O 4 as well as increase the tolerance in acidic media of NiCo 2 O 4 . Additional, the Co 2 P is oxidized to oxides/hydroxides species during the electrocatalytic reaction , which acts as the active centers of the electrocatalysis . The Co 2 P@NiCo 2 O 4 catalyst can be used as an effective bifunctional synergistic center in a wide range of pH values (from 0 to 14).
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
WATER AIR AND SOIL POLLUTION
·
2025
·Vol. 236
·期 12
·1-17
·
IF 3
Zheng Tianwen,Huang Kangping,Wang Moxi,Leng Wenpeng,Wu Naijin,Zhi Liqin,Li Peizhong,Luo Huilong,Wang Haijian,Wang Jiajia,Luo Nan,Wei Wenxia
DNAPLs are volatile, hardly degradable, highly toxic, and low solubility, which seriously threatens the ecological environment system and human health. While the fine characterization of DNAPLs migration process in porous media is crucial for remediating the contaminated sites. In order to finely characterize the migration process of DNAPLs in porous media, trichloroethylene (TCE) was selected as a typical DNAPLs pollutant in this paper. Then, based on the laboratory sand box model, image method and electrical resistivity tomography (ERT) technology were used to monitor the migration process of DNAPLs in saturated heterogeneous and homogeneous porous media, and the migration rules of TCE in different porous media were discussed and verified to achieve fine characterization of pollutant. The results of the sand box experiment indicated that when the particle size of heterogeneous quartz sand was small, TCE mainly migrated horizontally, and with the increase of quartz sand particle size, the vertical migration gradually dominated. For the homogeneous quartz sand media, TCE was also mainly horizontally migrated, supplemented by vertical migration. With the increase of pollutant injection time, TCE was mainly vertically migrated. When approaching the bottom of the sand box, the vertical migration speed of TCE in both heterogeneous and homogeneous quartz sand media slowed down, and the DNAPLs contamination pool could be formed at the bottom of the sand box. Generally, this paper uses the image method to visually reflect the migration of DNAPLs, and indirectly characterizes the distribution characteristics of DNAPLs by ERT technology, which is of great significance for studying the migration rule of DNAPLs and determining the pollution scope and degree, and can provide certain guiding value for fine characterization and low-cost remediation of DNAPLs pollutants in actual contaminated sites.
研究领域:
环境科学
·
水文地质学
·
污染物迁移
·
地球物理学
·
环境修复
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Kai Liu,Zizai Ma,Zihao Wan,Xiaoguang Wang
In this article, the hydrogen evolution performance in 0.5 M H 2 SO 4 and 1.0 M KOH is improved by introducing N atoms into Ni 2 P/Co 2 P through high-temperature doping (N–Ni 2 P/Co 2 P). N–Ni 2 P/Co 2 P has a lower overpotential than Ni 2 P/Co 2 P, which can achieve cathodic current densities of 10 mA cm −2 , 100 mA cm −2 at overpotentials of 48 mV, 228 mV in 1.0 M KOH and 63 mV, 211 mV in 0.5 M H 2 SO 4 . Density functional theory (DFT) results found that the introduction of N atoms changed the electronic structure of the catalyst. Due to the forward shift of d-band center, the binding force between the catalyst and H∗ is enhanced, providing favorable conditions for hydrogen evolution. Furthermore, the results of scaled-up tests show that 5 cm × 5 cm N–Ni 2 P/Co 2 P electrodes still exhibit superior performance, revealing a prospect of industrialization.
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
Journal of Materials Chemistry A
·
2025
·
IF 9.5
Wenhao Liu,Wei Li,Zhao Liang,Yufei Feng,Shaobo Ye,Chenchen Yue,Rui Ming,Xuyang Lu,Weiyou Yang,Qing Shi
The development of efficient and stable catalysts for oxygen evolution reaction (OER) is critical for the progress of electrocatalytic alkaline water and seawater hydrogen production. Herein, we report a Se-vacancy-rich Fe-doped NiSe nanosheets (VSe-FeNiSe/NFF) with remarkable OER performance in both alkaline and seawater media. It is revealed that the Se vacancies significantly promote the structural reconstruction during the OER process, which facilitates the formation of highly active NiFeOOH and SeO₄²⁻ species, thus delivering exceptional catalytic activity and stability. In alkaline media, they require an overpotential of 242 mV to achieve a current density of 100 mA cm-2, with a low Tafel slope of 27.2 mV dec-1 and robust stability over 500 h. Meanwhile, in seawater media, they just require an overpotential of 253 mV to achieve 100 mA cm-2, with a Tafel slope of 37.8 mV dec-1. Impressively, they could be operated stably for 100 h at 100 mA cm-2. This work not only elucidates the roles of Se vacancies in the reconstruction of selenides during the OER process, but also offers meaningful insight on exploring advanced electrocatalysts for OER in both alkaline water and seawater media.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Xin Zhao,Zheng Zhang,Xun Cao,Jun Hu,Xinghua Wu,Andrew Yun Ru Ng,Guo-Ping Lu,Zhong Chen
In this study, we conduct comprehensive experimental and theoretical investigations on the hydrogen evolution reaction (HER) preformation of FeP electrode in acidic and alkaline solutions. Theoretically, bulk Fe-O bond is unfavorable, but surface Fe-O bond is favorable and plays a negative role for HER. The presence of oxygen bonds (native or formed during reaction) is the root source of the reduced HER activity. Surface treatment in 37% HCl solution removes the oxide layer and significantly improves the HER performance, especially in alkaline solution. After etching, the overpotentials in 0.5 M H 2 SO 4 are 79 and 95 mV at 10 and 20 mA cm −2 , respectively. The ones in 1 M KOH are 95 and 102 mV at 10 and 20 mA cm −2 , respectively. Long-term instability in alkaline solution is caused by the presence of oxygen in the electrolyte. Good stability can be realized by removing oxygen from the solution.
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
·
2022
·
IF 6.371
Peng Zuo,Xujing Ji,Weizhou Jiao,Ruixin Wang
Herein, the ultrafine molybdenum carbide/nitride (Mo 2 C/Mo 2 N) heterojunction loaded by nitrogen (N), phosphorus (P)-codoped carbon matrix with hierarchical porous (PNC) is prepared in-situ by fabricating the ternary complex of silica (SiO 2 ) nanoparticles, chitosan (CS) and phosphomolybdic acid (PMo 12 ) as precursor, followed by annealing and hydrofluoric acid (HF) etching. Due to the excellent structural characteristics of the optimized catalyst Mo 2 C/Mo 2 N@PNC-8-2, including the Mo 2 C/Mo 2 N heterojunction and its uniform dispersion in PNC, P-doping in Mo 2 C/Mo 2 N, Mo vacancies, the strong interface coupling between Mo 2 C/Mo 2 N heterojunctions and PNC, as well as the connected macroporous channels and hierarchical porous structure, etc., not only large numbers of active sites are exposed, but also the electron density distribution around Mo atoms is tuned. Therefore, the charge/mass transport is greatly improved, resulting in the more superior hydrogen evolution activity of Mo 2 C/Mo 2 N@PNC-8-2 than that of the single-phased Mo 2 C or Mo 2 N counterpart, with lower overpotentials of 62 or 97 mV to achieve10 mA cm −2 in alkaline or acidic solution, respectively. Moreover, Mo 2 C/Mo 2 N@PNC-8-2 still shows excellent long-term durability. This study opens up a new idea for designing highly efficient electrocatalysts via integrating heterojunction, defects, heteroatom doping, and hierarchical porous structure.
研究领域:
材料科学
·
电催化
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
·
IF 4.084
Ruijing Wang,Peng Sun,Qin Yuan,Rongrong Nie,Xuefeng Wang
Metal-embedded nitrogen-doped carbon materials have been proposed as novel hydrogen evolution reaction (HER) catalysts to replace platinum-based materials, while these alternatives usually exhibit low activity and gradual deactivation during their use. Here, leaf-like cobalt-embedded nitrogen-doped porous carbon sheet (Co-NC) for the HER is obtained by simple pyrolysis of a two-dimensional metal organic framework . The Co-NC annealed at 800 °C exhibits large surface area and the active metallic cobalt species embedded in the N-doped carbon layers , which leads to the lower overpotential, higher current density , and superior durability in alkaline media . However, the Co-NC annealed at 600 °C shows abundant nitrogen-coordinated cobalt species, which favors the high HER activity under acidic condition. These structural properties of the Co-NC enable the efficient HER activity by increasing the active sites and enhancing mass transfer of water molecules or protons at the interface where the reaction takes place.
研究领域:
材料科学
·
电化学
·
能源催化
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2022
·Vol. 57
·期 2
·1036-1043
·
IF 4.682
Chen Xue-Qiang,Xie Lina,Cao Ming,Hu Wenjing,Gong Lifei,Fang Shiqiang
Inspired by inorganic oligomers, we herein develop a novel inorganic gel based on calcium oxalate oligomers, and the crystallization morphology has been studied initially in this paper. The prepared oligomer is translucent gel and can exist stably in ethanol, but in aqueous medium it will change from gel to powder. In the crystallization process, because of the volatile speed of solvent and capping agent TEA at different temperature, CaC 2 O 4 oligomer gels (COOGs) exhibited distinct crystallization behavior and morphology. Compared with conventional inorganic crystallization, the crystallization process of the gel at room temperature shows a tendency to gradually extend to the inside of the gel. Moreover, the XRD pattern and SEM images shown that the COOGs achieved distinctly different crystal morphology under different temperature. These provide a preliminary research foundation for the crystallization behavior and control conditions of inorganic gels. Graphical abstract
研究领域:
材料科学
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Chemistry
·
2022
·
IF 13.599
Zhen Zhang,Haijun Liu,Liwen Ni,Zhi-Liang Zhao,Hui Li
The hydrogen evolution reaction (HER) is the cathodic process of water splitting, and its reverse, the hydrogen oxidation reaction (HOR), is the anodic process of an H 2 -O 2 fuel cell; both play important roles in the development of hydrogen energy. The rational design and scalable fabrication of low-cost and efficient bifunctional catalysts for the HER/HOR are highly desirable. Herein, ultrasmall Mo-Ru nanoalloy (Mo 0.5 Ru 3 and MoRu 3 ) particles uniformly distributed on mesoporous carbon (MPC) were successfully synthesized by a simple method that is easy to scale up for mass production. After the incorporation of Mo atoms, the as-prepared Mo 0.5 Ru 3 and MoRu 3 nanoalloys maintain a hexagonal-close-packed crystal structure. In acidic media, Mo 0.5 Ru 3 exhibits excellent Pt-like HER and HOR activity, as well as good stability. Density functional theory (DFT) calculations reveal that the H adsorption free energy (Δ G H* ) on the Mo 0.5 Ru 3 (0 0 1) surface (−0.09 eV) is much closer to zero than that of metallic Ru (−0.22 eV), which contributes to the enhanced catalytic activity. In alkaline media, Mo 0.5 Ru 3 also presents outstanding HER and HOR activity, even significantly outperforming Pt/C. The DFT results confirm that optimal binding energies with H* and OH* intermediate species, and low energy barriers in the water dissociation and formation steps, efficiently accelerate the alkaline HER/HOR kinetics of Mo 0.5 Ru 3 . This study provides a new avenue for the scalable fabrication of high-efficiency bifunctional electrocatalysts for the HER and HOR in both acidic and alkaline media.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Lu Tian,Dazhong Zhong,Tao Zhao,Yi Liu,Lu Hao,Qiang Fang,Xuelei Lang,Xin Zhao,Genyan Hao,Guang Liu,Jinping Li,Qiang Zhao
Developing highly efficient OER catalysts is essential for producing hydrogen from water electrolysis to compensate for conventional fossil fuel shortages. Here, the oxygen-vacancy-rich heterostructure grown on the Ni foam (NF) (Co 3 O 4 @Fe-B-O/NF) is fabricated. The synergistic effect between Co 3 O 4 and Fe-B-O has been proven effectively modulate the electronic structure and produce highly active interface sites, ultimately leading to enhanced electrocatalytic activity. Co 3 O 4 @Fe-B-O/NF requires an overpotential of 237 mV to drive 20 mA cm −2 in 1 M KOH, and 384 mV to drive 10 mA cm −2 in 0.1 M PBS, superior to most catalysts currently used. Moreover, Co 3 O 4 @Fe-B-O/NF as an oxygen evolution reaction (OER) electrode shows great potential in overall water splitting and CO 2 reduction reaction (CO 2 RR). This work may provide effective ideas for designing efficient oxide catalysts.
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
LANGMUIR
·
2024
·
IF 3.7
Liming Zeng,Bang Yuan,Qing Zhou
Oxygen evolution reaction (OER) is a multistep proton-coupled four-electron process with sluggish kinetics, which seriously limits the hydrogen production efficiency, thus it is of great importance to develop an efficient and stable OER catalyst. In this study, a two-step differential pyrolysis strategy is employed to design a three-dimensional porous microstructured material consisting of RuOx nanoparticles coated by a thin-layer carbon, where the active particles were isolated in separate chambers and the RuOx nanoparticles mainly existed in the form of a heterogeneous interface between RuO2 and partial metallic Ru. The preparation parameters of the catalysts are optimized via combining transient and steady-state polarization properties, and the target catalyst Cat-500–1.5t shows the best OER catalytic performance after ca. 60 h of a chronopotentiometry test in an acidic medium with a much smaller performance change than other samples. The unique design of adopting a carbon layer to form separate reaction chambers largely mitigates the excessive oxidation loss of the active components under strong oxidation potential. The suitability of the catalyst with the loaded substrate and test media is explored, and in an acidic medium, the carbon paper is much better than the titanium fiber, while in an alkaline medium, the titanium fiber is obviously superior to the carbon paper. On both carbon paper and titanium fiber, the performance in an alkaline medium outperforms that in an acidic medium, and the possible reasons for the performance difference are analyzed. Herein, to obtain the actual electrocatalytic performance, the optimal design of the catalyst structure and matching suitable conductive substrate in a specific medium are quite necessary, which provides a feasible strategy for the acquisition of efficient and stable electrocatalysts and the desirable presentation of performance.
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
Advanced Materials Technologies
·
2023
·Vol. 8
·期 10
·2201985
·
IF 6.8
Chao Du,Xiang-Kun Li,Di Zhou,Shao-Fei Wang,Rui-Tao Li,Xiao-Gang Yao,Hui-Xing Lin,Hai-Yi Peng,Tao Zhou,Shi-Kuan Sun,Song Xia,Zhuo Xu
Array antenna is of great significance in realizing the Sub-6 GHz fifth-generation (5G) mobile communication systems, however, its utilization in the base station systems implementation is limited due to high power consumption. In this paper, a high radiation efficiency 4 × 4 cylindrical dielectric resonator antenna (CDRA) array fabricated using the temperature stable 0.8Zn 2 SiO 4 -0.2TiO 2 composite ceramic is proposed. TiO 2 -doped Zn 2 SiO 4 composite ceramics are synthesized by the conventional solid-state method. Notably, 0.8Zn 2 SiO 4 -0.2TiO 2 composite ceramic sintered at 1250 °C demonstrates excellent microwave dielectric properties with dielectric constant (ε r ≈ 8.24), high-quality factor ( Q × f ≈ 35 000@8.08GHz), and the temperature coefficient of resonant frequency ( TCF ≈ +4.6 ppm °C −1 ). Moreover, the composite ceramic CDRA array is designed by exciting fundamental HE 11δ mode using the aperture coupling microstrip feeding network. The fabricated composite ceramic based 4 × 4 CDRA array has enhanced measured radiation efficiency of up to 87%, high gain of 17.85 dBi and is a promising candidate for utilization in Sub-6 GHz 5G Base Station communications systems.
研究领域:
通信工程
·
材料科学
✓ 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）