Guiquan Liu,Shiyu Li,Rumisa Baikeri,Guorong Wang,Zhiliang Jin
Metal-organic skeleton (MOF) with adjustable pore skeleton and finely reaction sites has been widely accepted in the application of high-performance supercapacitors. Here, the Se-Co-MOF-1 nano-particles obtained by modified doped Se element to Co-MOF and the CoV 3 -MOF nano-sheets obtained by in-situ doped V element in Co-MOF. As a result, Se-Co-MOF-1 and CoV 3 -MOF electrode materials have more electrochemical reactivity, better conductivity and better stability. At a certain current density, Se-Co-MOF-1 and CoV 3 -MOF electrode materials have better mass-specific capacitance and better rate performance than Co-MOF. Furthermore, the Se-Co-MOF-1//AC ASC and CoV 3 -MOF//AC ASC are also assembled, which show relatively excellent power density and energy density compared to similar work reported. The Se-Co-MOF-1//AC ASC and CoV 3 -MOF//AC ASC after 10,000 cycles, their mass-specific capacitance retention rate are still 70.00 %, which further shows the reliable stability of Se-Co-MOF-1 and CoV 3 -MOF electrode materials. This result proves that the synthetic schemes of MOF nano-sheets/nano-particles can be selected as the source of the strategy for preparing excellent electrode materials.
The Gibbs free energy of hydrogen adsorption at the edge of molybdenum disulfide (MoS 2 ) is close to that of Pt, meaning that MoS 2 is the best candidate to replace Pt-based materials. However, easy agglomeration between layers to mask active sites, lack of catalytic activity in the basal planes, and poor electronic conductivity make MoS 2 exhibit dissatisfactory hydrogen evolution reaction (HER) catalytic performance. Here, we successfully construct a van der Waals heterostructure stacked alternately with Mo(SSe) 2-x and graphene (Mo(SSe) 2-x /G) to enhance its catalytic ability. The introduction of Se into MoS 2 and the thermal treatment induce the sample to generate more anion vacancies. Theoretical and experimental results demonstrate the constructed van der Waals heterostructure, the introduced Se element, and the increased anion vacancies are in favor of promoting the number of active sites and improving the electronic conductivity of the catalyst. Therefore, Mo(SSe) 2-x /G exhibits superior HER catalytic performance (the overpotentials of 137 mV and 136 mV at a current of 10 mA cm −2 ) and long-term stabilities (>90 h and 140 h at a current density of 20 mA cm −2 ) in both acidic and alkaline media.
危险品化学品经营许可证（带存储）