The rational construction of heterogeneous interfacial engineering presents a critical strategy for advancing efficient electrochemical water-splitting development.Here,a bimetallic sulfide-coupled MoNi alloy heterost...The rational construction of heterogeneous interfacial engineering presents a critical strategy for advancing efficient electrochemical water-splitting development.Here,a bimetallic sulfide-coupled MoNi alloy heterostructure catalyst(VMoS/MoNi)is synthesized via hydrothermal and sulfidation methods for high-performance alkaline water electrolysis.Benefiting from interfacial coupling within the VMoS/MoNi catalyst,the active sites are enriched,and electron transfer is promoted,leading to enhanced synergy and collaboration in electrocatalytic reactions.As a result,at 10 mA·cm^(-2),the VMoS/MoNi catalyst demonstrates excellent HER(26 mV)and OER(223 mV)performance.VMoS/MoNi catalysts used as double electrode in an alkaline electrolytic assembly are noteworthy for achieving a cell voltage of 1.56 V at 10 mA·cm^(-2),a significant improvement above most previously reported bifunctional electrocatalysts.This result provides further momentum for the design of heterostructure electrocatalysts,advancing the study of renewable energy conversion and storage.展开更多
In this paper, we investigate flows with moving contact lines on curved solid walls on a dual-resolution grid using a diffuse-interface immersed-boundary（DIIB） method. The dual-resolution grid, on which the flows ar...In this paper, we investigate flows with moving contact lines on curved solid walls on a dual-resolution grid using a diffuse-interface immersed-boundary（DIIB） method. The dual-resolution grid, on which the flows are solved on a coarse mesh while the interface is resolved on a fine mesh, was shown to significantly improve the computational efficiency when simulating multiphase flows. On the other hand, the DIIB method is able to resolve dynamic wetting on curved substrates on a Cartesian grid, but it usually requires a mesh of high resolution in the vicinity of a moving contact line to resolve the local flow. In the present study, we couple the DIIB method with the dual-resolution grid, to improve the interface resolution for flows with moving contact lines on curved solid walls at an affordable cost. The dynamic behavior of moving contact lines is validated by studying drop spreading, and the numerical results suggest that the effective slip length λ_n can be approximated by 1.9Cn, where Cn is a dimensionless measure of the thickness of the diffuse interface. We also apply the method to drop impact onto a convex substrate, and the results on the dual-resolution grid are in good agreement with those on a single-resolution grid. It shows that the axisymmetric simulations using the DIIB method on the dual-resolution grid saves nearly 60% of the computational time compared with that on a single-resolution grid.展开更多
基金supported by the National Natural Science Foundation of China(No.22369025)Yunnan Applied Basic Research Projects(Nos.202201AT070095,202301AT070098,202301AT070107,202401AT070438,and 202401AT070433)+2 种基金Education Reform Research Project of Yunnan University(No.2021Z06)Yunnan University Graduate Student Practice and Innovation Program(Nos.ZC-23234269,ZC-23235291,KC-23236398,and KC-23234063)Yunnan Revitalization Talent Support Program。
文摘The rational construction of heterogeneous interfacial engineering presents a critical strategy for advancing efficient electrochemical water-splitting development.Here,a bimetallic sulfide-coupled MoNi alloy heterostructure catalyst(VMoS/MoNi)is synthesized via hydrothermal and sulfidation methods for high-performance alkaline water electrolysis.Benefiting from interfacial coupling within the VMoS/MoNi catalyst,the active sites are enriched,and electron transfer is promoted,leading to enhanced synergy and collaboration in electrocatalytic reactions.As a result,at 10 mA·cm^(-2),the VMoS/MoNi catalyst demonstrates excellent HER(26 mV)and OER(223 mV)performance.VMoS/MoNi catalysts used as double electrode in an alkaline electrolytic assembly are noteworthy for achieving a cell voltage of 1.56 V at 10 mA·cm^(-2),a significant improvement above most previously reported bifunctional electrocatalysts.This result provides further momentum for the design of heterostructure electrocatalysts,advancing the study of renewable energy conversion and storage.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11425210,11621202 and 11672288)
文摘In this paper, we investigate flows with moving contact lines on curved solid walls on a dual-resolution grid using a diffuse-interface immersed-boundary（DIIB） method. The dual-resolution grid, on which the flows are solved on a coarse mesh while the interface is resolved on a fine mesh, was shown to significantly improve the computational efficiency when simulating multiphase flows. On the other hand, the DIIB method is able to resolve dynamic wetting on curved substrates on a Cartesian grid, but it usually requires a mesh of high resolution in the vicinity of a moving contact line to resolve the local flow. In the present study, we couple the DIIB method with the dual-resolution grid, to improve the interface resolution for flows with moving contact lines on curved solid walls at an affordable cost. The dynamic behavior of moving contact lines is validated by studying drop spreading, and the numerical results suggest that the effective slip length λ_n can be approximated by 1.9Cn, where Cn is a dimensionless measure of the thickness of the diffuse interface. We also apply the method to drop impact onto a convex substrate, and the results on the dual-resolution grid are in good agreement with those on a single-resolution grid. It shows that the axisymmetric simulations using the DIIB method on the dual-resolution grid saves nearly 60% of the computational time compared with that on a single-resolution grid.
