JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Zhiqiang Zhang,Xiaofeng Lin,Shuli Tang,Haijiao Xie,Qitong Huang
Efficient, stable and low-cost catalysts are essential for improving the efficiency of hydrogen evolution reactions . Herein, the MoO 2 @Ni 2 P heterostructure electrocatalyst was synthesized in a self-supported system on a carbon paper (CP) by two-step deposition and phosphorization at low temperature. The self-supported nanoarray structure makes the catalyst to effectively and efficiently transfer electrons and exposes more of its active sites. Moreover, the strong interaction between Ni 2 P and MoO 2 helps to effectively optimize the electronic structure. The density of states calculations demonstrate that there is an increase in the density of electronic states near the MoO 2 /Ni 2 P Fermi level . This shows that MoO 2 /Ni 2 P has fast charge transfer kinetics. MoO 2 modulates the d-band center of nickel, resulting in moderate adsorption/desorption of hydrogen. The above results show that MoO 2 @Ni 2 P has good hydrogen evolution activity. The experimental results show that the overpotential (η 10 ) of MoO 2 @Ni 2 P/CP in the alkaline environment is only 57 mV with a Tafel slope of 61 mV dec −1 . It is similar to the commercial noble-metal catalysts and outperforms most reported 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
ANALYTICAL CHEMISTRY
·
2019
·
IF 6.35
Yu Cao,Pei Liang,Qianmin Dong,Dan Wang,De Zhang,Lisha Tang,Le Wang,Shangzhong Jin,Dejiang Ni,Zhi Yu
Recently, more and more attention has been given to a semiconductor oxide-based surface-enhanced Raman spectroscopy substrate for its great stability and biocompatibility. However, its poor SERS sensitivity limits the applications of semiconductor oxide SERS substrates. In this paper, we provide a facile reduction method to modulate oxygen vacancy concentrations in oxide SERS substrates. Using MoO2 as an example, the resonance coupling as well as charge transfer between the semiconductor oxide SERS substrate and the target molecules were promoted for the reason of artificial oxygen vacancy embodied in the Raman signals being improved. By using the TEM, SEM, and XPS measurements, we confirmed that we successfully prepared defective MoO2–x with a polycrystalline surface. MoO2–x modulated oxygen vacancy treated with 6 wt % Li shows a very high detection sensitivity of 10–8 M (4.79 ug/L) for R6G, and the intensity of the Raman signal was highly enhanced. Because of the existence of defective energy levels, resonance coupling, as well as charge transfer between semiconductor and molecules, was obviously promoted. More importantly, the method of modulating oxygen vacancy can be widely used in semiconductor oxide materials for its chemical enhancement capacity can be promoted by artificial oxygen vacancy.
研究领域:
材料科学
·
光谱学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Liang-pei Hou,Rong-xiang Zhao,Xiu-ping Li,Xiao-han Gao
A series of catalysts of composition X -MoO 2 /g-C 3 N 4 ( X = 0, 0.5, 1, 3, 5 wt.%) were successfully synthesized by calcination of a mixture of (NH 4 ) 6 Mo 7 O 24 ·4H 2 O and g-C 3 N 4 . Oxidative desulfurization experiments were conducted using X -MoO 2 /g-C 3 N 4 as a catalyst, H 2 O 2 as an oxidant, and ionic liquids (ILs) as extraction agents. Catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared (FT-IR), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), and Brunauer-Emmett-Teller analysis (BET). Characterization results suggested that MoO 2 was present in the catalyst and its crystallinity improved with increased Mo-loading. The catalysts had a larger specific surface area due to the presence of MoO 2 dispersed on g-C 3 N 4 . Experimental results showed that 3%-MoO 2 /g-C 3 N 4 had the highest catalytic activity among all the catalysts tested. A desulfurization rate of 96.0% was achieved under optimal conditions. Through gas chromatography-mass spectrometry (GC–MS) analysis, it was shown that dibenzothoiphene sulfone was the sole product of the oxidation desulfurization reaction. An apparent activation energy of 61.1 kJ/mol was estimated based on Arrhenius equation. The activity of 3%-MoO 2 /g-C 3 N 4 slightly decreased after six runs. A possible mechanism for the reaction has been proposed.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Chuang Li,Haeseong Jang,Min Gyu Kim,Liqiang Hou,Xien Liu,Jaephil Cho
Designing highly efficient Pt-free electrocatalysts with low overpotential for the alkaline hydrogen evolution reaction (HER) remains a significant challenge. In this paper, we successfully construct Ru-incorporated oxygen-vacancy-enriched MoO 2 nanosheets (Ru/MoO 2−x ) for the HER through a “one stone two birds” strategy. This strategy can solve two urgent problems simultaneously, the intrinsic electrochemical activity of original MoO 2 is far from satisfactory and the H 2 O adsorption/dissociation abilities of Ru are weak. Specifically, the oxygen-vacancy-enriched MoO 3 serves as an excellent platform for anchoring and trapping Ru ions. In-depth analyses indicate that the incorporation of Ru nanoclusters induces transition from MoO 3 to MoO 2 , generates oxygen vacancies, and creates Ru-O-Mo sites. The synergistic effect of Ru nanoclusters , Ru-O-Mo sites and oxygen-vacancy-enriched MoO 2 will endow the obtained catalyst excellent electrocatalytic activity. In particular, the optimal Ru/MoO 2−x electrocatalyst delivered a low overpotential of 29 mV at 10 mA cm −2 in a basic electrolyte.
研究领域:
电化学
·
材料科学
·
催化
·
能源材料
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2019
·Vol. 7
·期 31
·9545-9555
·
IF 6.641
Yunrui Tian,Haishun Du,Miaomiao Zhang,Yayun Zheng,Qingping Guo,Huaiping Zhang,Jujie Luo,Xinyu Zhang
Herein, we present an ultrafast microwave approach for fabricating MoS2/MoO2@CNT nanocomposites toward supercapacitor electrodes with excellent cycle stability. The surface chemistry, crystalline structure and morphology of the as-produced nanocomposites were characterized by FTIR, XRD, XPS, EDS and SEM. It was found that MoS2/MoO2 nanoparticles could grow uniformly on the surface of CNTs, and the CNTs can provide a transport path for ions in electrolytes and reduce energy loss, thus leading to enhanced electrochemical performance of the resultant nanocomposites. Electrochemical results showed that the capacitance of the nanocomposite electrode was increased by 187.1% after 25 000 cycles at a current density of 5 A g−1, indicating outstanding cycling stability. Also, the maximum capacitance of the optimized MoS2/MoO2@CNT electrode can reach 228.4 F g−1 at 0.5 A g−1. Moreover, an asymmetric supercapacitor (MoS2/MoO2@CNT//AC) was assembled which exhibited a maximum energy density of 11.88 W h kg−1 and a power density of 2 kW kg−1, respectively. Intriguingly, the asymmetric supercapacitors could successfully light three LED lights for 5 minutes, showing their great practical application potential in portable supercapacitors.
研究领域:
材料科学
·
电化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2023
·
IF 6.6
Yabing Sun,Haoju Li,Xin Zhou,Yonggang Min,Yannan Qian
It is well known that the balanced charge injection helps prepare high-performance red light-emitting diodes (LEDs) in the electroactive material CsPbBr x I 3- x quantum dots (QDs). Employing a hydrothermal method, we synthesized MoO 2 nanocrystals and doped them into Poly(3,4-ethylenedioxythiophene) /poly(styrenesulfonate) (PEDOT:PSS). The results show that the synthesized MoO 2 nanocrystals can modulate the work function of PEDOT:PSS and enhance the conductivity of the PEDOT:PSS films, which is attributed to disrupting the hydrogen bond between PEDOT and PSS, and inducing the transition of PEDOT from benzoid to quinoid structure. In the PEDOT:PSS- x MoO 2 film, the work function increases from 4.9 eV to 5.09 eV when the content of x is 15%, which reduces the energy barrier between the PEDOT:PSS- x MoO 2 and the hole transport layer: poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)-benzi (poly-TPD), thus promoting the hole transport and improving the V on of the devices. Additionally, the device's external quantum efficiency (EQE) reaches a maximum value of 7.53% at x = 15% enabling an improvement of 2.6 times over the base device (EQE=2.10%). This work proves that PEDOT:PSS- x MoO 2 as a hole transport layer is an effective material for preparing high-performance QD-LEDs.
研究领域:
材料科学
·
光电技术
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Jinxiu Qian,Fan Yang,Hongchen Liu,Guohua Li,Siyuan Sun,Xiaoyun Zhang,Guang Ma,Jiating Cheng,Mingjie Li,Ni Wu,Xi Li,Yongfeng Li
Achieving efficient production of hydrogen and obtaining high value-added products can maximize energy efficiency, but challenging. Herein, a nanoarray-structured heterojunction catalyst (CoP-MoO 2 /NF) was proposed as a potent bifunctional electrocatalyst for hydrogen evolution reaction (HER) and 5-hydroxymethylfuran oxidation reaction (HMFOR). Density Functional Theory (DFT) showed that heterojunction enhanced the adsorption of reactants on the electrocatalyst surface, the CoP-MoO 2 /NF exhibits excellent HER activity with an overpotential of 37 mV and a Tafel slope of 43 mV·dec −1 at 10 mA·cm −2 . Also, nearly 100% HMF conversion and 98.6% FDCA selectivity demonstrate the favorable performance of the material toward HMFOR. The work here shows a way for producing hydrogen in the future that is low-cost, efficient, reliable and also adds value to the final product.
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 Materials Chemistry A
·
2021
·Vol. 9
·期 22
·13001-13007
·
IF 12.732
Xufei Liu,Peng Mei,Yu Dou,Rui Luo,Yusuke Yamauchi,Yingkui Yang
The urgent desire for high-energy lithium-ion batteries (LIBs) has motivated scientists to develop large-capacity electrode materials with innovative compositions and/or architectures. Herein, we report a three-dimensional (3D) hierarchical MoO2/MoS2/C heterostructure composed of tiny crumpled nanosheets arrayed on a larger lamellar substrate through a facile hydrothermal polymerization–carbonization route. Benefiting from the intrinsically high capacity contribution from Mo-based components, expedited charge transfer from the intimately integrated carbon matrix, sufficient electrolyte penetration, rapid lithium transportation and volume change tolerance from the 3D hierarchical heteroconfiguration, our MoO2/MoS2/C demonstrates an appreciable reversible capacity (787.5 mA h g−1 at 0.1 A g−1), outstanding rate performance (80% capacity retention even as the current density increases tenfold), and superior long-term cyclability with a slow fading of 0.02% per cycle over 2000 cycles, holding great promise for the fabrication of desirable LIBs with high energy density and long lifetimes.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2025
·
IF 4.7
Ziwei Chen,JinChang Zhao,Qing Li,Rufen Chen,HuiJiao Zhang,Hui Zhao,Kezhong Wu
The synergistic coupling of different metal species endows mixed transition metal oxides (MTMOs) as electrode materials for supercapacitors with multiple redox reaction pathways and enhances the electronic conductivity. In this study, three MoO 2 @FeMoO 4 electrode materials were derived from the precursor PMo 12 @MIL-101(Fe) by pyrolysis at 600 °C, 700 °C, and 800 °C under an O 2 atmosphere. The precursor was composed of polyoxomolybdate (H 3 PMo 12 O 40 , PMo 12 ) and Fe-based metal-organic frameworks (MOFs) MIL-101(Fe). The structural characteristics of the three obtained MoO 2 @FeMoO 4 composites were characterized by XRD, XPS, SEM, and N 2 adsorption measurement. Then, the effects of the pyrolysis preparation temperature for the MoO 2 @FeMoO 4 composites on the energy storage performance of the supercapacitor electrode were evaluated by cyclic voltammetry (CV) and galvanostatic charge/discharge tests. Among three electrodes, the specific capacitance of 339.6 F g −1 of the obtained MoO 2 @FeMoO 4 (700 °C) electrode was the highest compared to 291.2 F g −1 of MoO 2 @FeMoO 4 (600 °C) and 209.7 F g −1 of MoO 2 @FeMoO 4 (800 °C) at a current density of 0.5 A g −1 in 1.0 M NaOH electrolyte. As a result, the different pyrolysis preparation temperatures can alter the atomic microelectronic state and geometric configuration of the MoO 2 @FeMoO 4 , which can construct a high-density Fe–Mo bimetallic multicatalytic active site, thus affecting the activity of the composites. The excellent pseudo-supercapacitance response of the MoO 2 @FeMoO 4 (700 °C) electrode can be ascribed to its larger S BET and greater number of voids, which can generate more Fe–Mo bimetallic active sites and facilitate the electrolyte diffusion, indicating high energy conversion efficiency for potential application in supercapacitors.
研究领域:
材料科学
·
电化学
·
纳米技术
·
储能
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2025
·
IF 8.3
Zhaoxing Li,Ming Xu,Ting Wang,Yating Yang,Yuanze Li,Mei Liu,Yubo Liu,Ming Feng
Exploring low-cost and highly efficient electrocatalysts with bifunctional activities of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is practically essential for overall water splitting. Nevertheless, perfectly balancing the catalytic behavior between HER and OER continues to be a great challenge due to their distinct conducting behaviors and free energies. Herein, an advanced bifunctional electrocatalyst based on P-doped defective MoS 2 /MoO 2 heterostructure integrated onto highly conductive carbon cloth has been constructed for overall water splitting in acidic media. By reasonably controlling reaction conditions, the MoS 2 /MoO 2 heterostructure can be rationally constructed and the corresponding sulfur vacancies can be well optimized. Meanwhile, the abundant oxygen vacancies can be also created during the heat transformation processes. Benefiting from the unique structural features that favor the active species adsorption and electron transfer, the resultant A-P-M-3/CC catalyst exhibits exceptional bifunctional electrocatalytic activity, with low overpotentials of 67 and 104 mV at 10 mA cm −2 for HER and OER, respectively. When coupled in a two-electrode electrolyzer, A-P-M-3/CC delivers 10 mA cm −2 at a low cell voltage of 1.44 V with good stability, surpassing most of similar electrocatalysts. This work offers a novel avenue for water splitting catalyst optimization.
研究领域:
材料化学
·
电催化
·
纳米材料
·
能源科学
·
表面科学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2025
·
IF 6.5
Shiqi Chen,Xinyu Wang,Can Liu,Jiapeng Yue,Zhiwei Yang,Qian Ye,Hao Xu,Yujian Zhang,Xinyi Xing,Jing Zhang
Rational design and controllable synthesis of oxygen functional groups on carbon/metal catalysts surface as the effective means to enhance catalytic performance, however, still remains a great challenge. Herein, to obtain the relationship between oxygen functional groups and catalytic performance, taking MoO 2 -C as an object, the correlation between the C=O, C-O, Mo O bonds and strengthened iron reduction is quantitatively assessed, with electrochemical experiments validating that this relationship arises from its influence on the electron transport process, specifically concerning the roles of electron donors and mediators. The metal–oxygen and C-O bonds synergistically enhance electron transport, whereas the C=O and C-O bonds exhibit an antagonistic effect on electron-mediated processes. The influence of the metal–oxygen bonds was found to stem from their role as an electron donor, while the carbon–oxygen bonds primarily modulate the material’s catalytic properties by altering its electron transfer characteristics. In this study, the C-O, C=O bonds, and metal–oxygen bonds, as the typical surface oxygen functional groups, were identified the mechanism by changing the electron supply and mediation to enhance the Fe 3+ reduction reaction in the Fenton system, which provided theoretical support and design ideas for the design of catalyst with excellent catalytic properties.
研究领域:
催化
·
表面化学
·
电化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Sustainable Energy & Fuels
·
2023
·Vol. 8
·期 3
·604-609
·
IF 5.6
Jinhui Zhang,Chuanhe Ma,Haixuan Gao,Jinchun Jiang,Hailong Wang
An over-thick MoSe2 layer and numerous voids at the absorbing layer inside and backside lead to a relatively low Jsc and PCE of CZTSSe solar cells. In previous studies, MoO2 and MoO3 sacrificial layers have been commonly used to eliminate those voids and reduce the thickness of MoSe2 layers. However, there is still no clarity about which one is more effective. In this work, we prepared MoO2 and MoO3 sacrificial layers on the surface of Mo-coated SLG substrates by air annealing and ammonia (NH3·H2O) etching, respectively. J–V testing shows that both MoO2 and MoO3 can effectively improve the Jsc and PCE of CZTSSe solar cells, wherein MoO3 is more effective. Comparative analysis shows that the electrical mechanism of Jsc and PCE improvement lies in the significant reduction of device series resistance (Rs). SEM images and XRD pattern results indicate that the reason for Rs decreasing is void elimination and MoSe2 layer thickness reduction from 600 nm to 270 nm after applying MoO3. With the aid of the MoO3 sacrificial layer, the PCE of the CZTSSe device increases from 7.51% to 9.58% (total area 0.21 cm2) without the MgF2 anti-reflection layer.
研究领域:
材料科学
·
太阳能
·
光伏技术
✓ 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）