ELECTROCHIMICA ACTA
·
2019
·
IF 5.383
Shuangyue Hou,Yue Lian,Zongying Xu,Dawei Wang,Chaolei Ban,Jing Zhao,Huaihao Zhang
the ball-flower like composite (NiS 2 @MoS 2 ) was successfully synthesized by a convenient two-step hydrothermal method using Ni(NO 3 ) 2 ·6H 2 O and (NH 4 ) 6 Mo 7 O 24 ·4H 2 O as precursors. MoS 2 nano-sheets, uniformly generated on NiS 2 surface, increases the surface roughness and porosity, and accelerates the electrons and ions transfer of the composite. The synergistic effect of Mo and Ni improves the conductivity of the materials. Furthermore, by controlling the atomic ratio of Mo to Ni in precursors, the composite MN-1 (the molar ratio of MoS 2 to NiS 2 is 1:1) with the best capacity performance was obtained. The morphology and composition were characterized by a variety of means, such as TEM, SEM, XPS, XRD, BET and EDX. The electrochemical measurement results exhibited high specific capacity (848.2 C g −1 at specific current of 1 A g −1 ) and good cycling stability (83.1% specific capacity retention after 10000 GCD cycles) of MN-1 in 6 M KOH. Furthermore, an asymmetric supercapacitor was assembled with MN-1 as positive electrode and activated carbon as negative electrode. When the power density is 0.8 kW kg −1 , its energy density reaches up to 37.2 Wh kg −1 . The present work may offer new design strategy for electrode materials .
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 SURFACE SCIENCE
·
2023
·
IF 6.7
Guang-Lan Li,Ying-Ying Miao,Xiang-Yue Qiao,Tian-Yu Wang,Fei Deng
Boosting the hydrogen and oxygen evolution reaction (HER/OER) on MoS 2 -based catalysts is a challenging scientific issue due to the activity of MoS 2 is significantly rely on the edge site which is limited in regular structure. Herein, a highly dispersed edge site-rich NiS 2 /MoS 2 /CNTs heterojunction catalyst is successfully developed via facile etching the nanoflower-like NiS 2 /MoS 2 spheres on carbon nanotubes (CNTs). Through expanding the lattice spacing of 2H-MoS 2 , generating abundant Mo-S edge sites ( i.e . generating a large number of unsaturated S atoms) together with enhancing the dispersity of NiS 2 /MoS 2 nanosheets, the etching posttreatment significantly regulates the electronic and geometric structure of NiS 2 /MoS 2 /CNTs. Further combining the extremely intimate electronic interaction between MoS 2 /NiS 2 heterogeneous interfaces, the optimal NiS 2 /MoS 2 /CNTs presents a preeminent alkali water splitting performance with overpotentials of 149 for HER and 315 mV for OER at 10 mA cm −2 , which are 29 and 35 mV lower than the catalyst before etch treatment (NiS 2 /MoS 2 /CNTs-p), respectively. Moreover, the electrolyzer assembled with NiS 2 /MoS 2 /CNTs drives a voltage of 1.73 V at 10 mA cm −2 and a continuous stable operation of 50 h toward overall water splitting.
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
CATALYSIS LETTERS
·
2019
·Vol. 149
·期 5
·1197-1210
·
IF 2.372
Wang Lina,Guo Tong,Sun Sen,Wang Yan,Chen Xiaoling,Zhang Kangning,Zhang Dongxia,Xue Zhonghua,Zhou Xibin
Abstract The electrocatalytic activity of transition metal dichalcogenides (TMDs) is largely dependent on the exposed massive active sites and electrical conductivity of the catalysts. In this work, a tree-like nanocomposite (NiS 2 /MoS 2 -RGO) which is composed of bimetal sulfide (NiS 2 /MoS 2 ) nanocomposites uniformly anchored on the surface of reduced graphene oxide (RGO) was successfully synthesized. As a catalytic material for the hydrogen evolution reaction (HER), the NiS 2 /MoS 2 -RGO composites exhibit significantly enhanced electrocatalytic activity and impressive long-term stability for the hydrogen evolution reaction over a wide pH range. The tree-like NiS 2 /MoS 2 -RGO nanocomposites afford a current density (η 10 ) of 10 mA/cm 2 at small overpotentials of 172, 144 and 229 mV, and have a small Tafel slope of 51, 82 and 103 mV/dec in acidic, alkaline and neutral solution, respectively. Further studies reveal that the effective activities benefit from the abundant active edge sites and defects of NiS 2 /MoS 2 nanocomposites and the excellent conductivity of RGO. Graphical Abstract
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 CATALYSIS
·
2023
·
IF 7.3
Hao Zhang,Qing Zhang,Guang-Ren Qian,Hong Liu,Jia Zhang,Yang Yue,Chen-Qi Gao,Wen-ying Li,Rui-Sen Jing
A series of new NiS 2 -MoS 2 - x ( x = 0–0.5) sphere-flower hybrids with different Ni/Mo molar ratios, synthesized via a one-pot hydrothermal method, were used as catalysts for hydrodesulfurization (HDS) of thiophene (TP) and 4,6-dimethyl-dibenzothiophene (4,6-DMDBT). The characterizations show that the microstructure of MoS 2 , including the size of MoS 2 nano-flowers, the length of MoS 2 slabs, and the number of defects, was regulated by changing Ni/Mo ratios. Increasing the Ni/Mo ratio in the NiS 2 -MoS 2 - x catalysts significantly boosts their HDS activity, with the optimum ratio being 0.2. In addition, the NiS 2 -MoS 2 -0.2 catalyst exhibits the best direct desulfurization performance, which is associated with the minimum ratio of average slab length ( L av ) to average stacking number ( N av ) as well as the highest concentration of Ni-promoted Mo sites and sulfur vacancies. Moreover, Ni-containing NiS 2 -MoS 2 - x catalysts, characterized by a highly stable sphere-flower configuration, exhibit superior structural stability and catalytic durability than the Ni-free NiS 2 -MoS 2 -0 catalyst.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2020
·
IF 5.825
Lei Wang,Haiyan Liu,Yu Fan,Pei Yuan,Deqi Huang,S. Ted Oyama,Tinghai Wang,Xiaojun Bao
In alumina-based catalysts the properties of the alumina support directly influence the structure (size, morphology, orientation, etc.) of the resulting active phase and ultimately determine the performance of the final catalysts. This paper presents a facile and efficient method for γ-Al 2 O 3 to simultaneously expose {111} facets with strong acidity and {110} facets with moderate basicity. It is shown that the metal oxides NiO x and MoO x can be selectively deposited and subsequently sulfided on the respective facets to form a NiS 2 -MoS 2 /Al 2 O 3 catalyst with substantially enhanced activity for thio-etherification reaction. By cooperative action of the active sites on the newly exposed facets, the catalyst is shown to have superior activity over a conventional NiMoS/Al 2 O 3 catalyst in the thio-etherification reaction between ethanethiol and isoamylene (2-methyl-2-butene) to yield ethylamyl thioethers. Our findings show that tuning the physicochemical properties via crystal facet engineering and inducing cooperative catalysis via preferential deposition of active metals open a novel avenue for the rational design and synthesis of high performance catalysts.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 19
·4876
·
IF 3.1
Hao Li,Feng Chen,Xinyang Wu,Dandan Wang,Yongpeng Ren,Yaru Li
In recent years, there has been significant interest in transition-metal sulfides (TMSs) due to their economic affordability and excellent catalytic activity. Nevertheless, it is difficult for TMSs to achieve satisfactory performance due to problems such as low conductivity, limited catalytic activity, and inadequate stability. Therefore, a catalyst with a heterostructure constituted of a nickel–iron-layered double hydroxide, nickel sulfide, molybdenum disulfide, and cerium dioxide was designed. At the current density of 10 mA cm−2in an alkaline solution, the catalyst exhibits a HER overpotential of 116 mV. In addition, an overpotential of 235 mV@150 mA cm−2was displayed for OER. The catalyst showed a good retention rate (94.7% for HER, 98.6% for OER) after 160 h stability tests. The excellent electrochemical performance is attributed to the following points: 1. The self-supporting three-dimensional hierarchical structure provides abundant sites, fast ion diffusion channels, and electron transfer paths, and ensures structural stability. 2. The strong interfacial electron interaction between Ni3S2/MoS2heterojunction and NiFe-LDH improves the OER reaction kinetics. 3. The Ce3+and oxygen vacancies in CeO2promote the dissociation of H2O and promote the HER reaction kinetics. This approach paves the way for developing highly efficient electrocatalysts for various electrochemical applications.
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
ACS Applied Nano Materials
·
2021
·
IF 5.097
Jingjing Yuan,Ling Jiang,Jianfei Che,Guangyu He,Haiqun Chen
Electrode material plays a critical role in both electrochemical energy storage and sensors, and there is an urgent need to develop novel electrode materials with high reactivity and catalytic activity. Herein, a multicomponent NiS2/MoS2/rGO electrode nanomaterial consisting of self-stacking NiS2 microblocks, hydrangea-like MoS2 nanosheets, and ultrathin reduced graphene oxide (rGO) nanolayers is synthesized via a facile two-step hydrothermal process. The ingenious combination of NiS2, MoS2, and rGO provides the nanocomposite good capacitance and sensitivity in electrochemical applications. As a result, the NiS2/MoS2/rGO nanocomposite exhibits a good specific capacitance of 645.3 F g–1 at 0.5 A g–1 and rate performance of 126.7 F g–1 at 10 A g–1. The assembled asymmetric supercapacitor of NiS2/MoS2/rGO//activated carbon delivers a high energy density of 19.4 Wh kg–1 at a power density of 156.1 W kg–1 for electrochemical energy storage. In addition, the electrochemical sensor based on a NiS2/MoS2/rGO nanocomposite modified onto glassy carbon electrode (GCE) shows superior activity toward detection of bisphenol A (BPA) compared with other reported electrochemical sensors. A wide linear range of 0.02–200 μM and a low detection limit of 2.1 nM can be obtained under the optimal conditions. This work provides insights into the development of multicomponent NiS2/MoS2/rGO electrode nanomaterial, including its facile synthesis method, good specific capacitance, and ultrasensitive detection of BPA, that exhibits bifunctional electrochemical applications.
研究领域:
材料科学
·
电化学
·
环境分析化学
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2019
·Vol. 9
·期 2
·292
·
IF 4.034
Zhi Zhang,Xuliang Lv,Yiwang Chen,Pin Zhang,Mingxu Sui,Hui Liu,Xiaodong Sun
For the purposes of strength, military equipment camouflage, and protecting the health of organisms, electromagnetic wave absorbing materials have received a lot of attention and are widely studied. In addition to having a strong absorption intensity and a wide effective absorption bandwidth, materials that are lightweight, thermally stable, and antioxidative are also highly desirable. In this study, we fabricated core–shell structured NiS2@MoS2nanospheres anchored on reduced graphene oxide (rGO) nanosheets (NiS2@MoS2/rGO) by a simple two-step hydrothermal method. The combination ratio was adjusted to achieve proper impedance matching. The electromagnetic parameters and the absorption performance were investigated in detail. A composite loaded with 30 wt.% of the sample achieved a minimum reflection loss (RL) value of −29.75 dB and the effective bandwidth (RL value of less than −10 dB) ranged from 4.95 GHz to 18.00 GHz (13.05 GHz), with a thickness ranging from 1.5 mm to 4.0 mm. This study proved that the generated significant interfacial polarization and synergetic interaction between components can result in NiS2@MoS2/rGO composites with enhanced electromagnetic absorption performance.Keywords:graphene;core–shell;heterostructure;electromagnetic absorption
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）