Transition metal phosphides(TMPs)have emerged as promising electrocatalysts to enhance the slow kinetic process of oxygen evolution reaction(OER).Framelike hollow nanostructures(nanoframes,NFs)provide the open structu...Transition metal phosphides(TMPs)have emerged as promising electrocatalysts to enhance the slow kinetic process of oxygen evolution reaction(OER).Framelike hollow nanostructures(nanoframes,NFs)provide the open structure with more accessible active sites and sufficient channels into the interior volume.Here,we report the fabrication of bimetallic Co-Fe phosphide NFs(Co-Fe-P NFs)via an intriguing temperature-controlled strategy for the preparation of precursors followed by phosphidation.The precursors,Co-Fe Prussian blue analogues(Co-Fe PBAs)are prepared by a precipitation method with Co^(2+)and[Fe(CN)_(6)]^(3−),which experience a structural conversion from nanocubes to NFs by increasing the aging temperature from 5 to 35℃.The experimental results indicate that this conversion is attributable to the preferentially epitaxial growth on the edges and corners of nanocubes,triggered by intramolecular electron transfer at an elevated aging temperature.The as-prepared Co-Fe-P NFs catalyst shows remarkable catalytic activity toward OER with a low overpotential of 276 mV to obtain a current density of 10 mA cm^(−2),which is superior to the reference samples(Co-Fe-P nanocubes)and most of the recently reported TMPs-based electrocatalysts.The synthetic strategy can be extended to fabricate Co-Fe dichalcogenide NFs,thereby holding a great promise for the broad applications in energy storage and conversion systems.展开更多
In step with reform and opening up, the Chinese system of anti-corruption charges has been progressively refined and elaborated. Its successive refinements and comprehensive transformation have resulted in a tight-kni...In step with reform and opening up, the Chinese system of anti-corruption charges has been progressively refined and elaborated. Its successive refinements and comprehensive transformation have resulted in a tight-knit network of anti-corruption criminal law and a dual system of charges. This system has made a remarkable contribution to combating corruption over the last three decades. More than the outcome of the natural evolution of legal logic, it also involves complex considerations of social transformation and reflects lawmakers＇ expectations of being able to prevent corruption at the institutional level. With the deepening and widening of reform and opening up, China＇s system of anti-corruption charges will inevitably develop towards the thorough abolition of the dual system of charges and the complete restoration of the unitary system.展开更多
基金supported by the National Natural Science Foundation of China(21872105 and 22072107)the Natural Science Foundation of Zhejiang Province(LQ20B030001 and LY20E020002)。
文摘Transition metal phosphides(TMPs)have emerged as promising electrocatalysts to enhance the slow kinetic process of oxygen evolution reaction(OER).Framelike hollow nanostructures(nanoframes,NFs)provide the open structure with more accessible active sites and sufficient channels into the interior volume.Here,we report the fabrication of bimetallic Co-Fe phosphide NFs(Co-Fe-P NFs)via an intriguing temperature-controlled strategy for the preparation of precursors followed by phosphidation.The precursors,Co-Fe Prussian blue analogues(Co-Fe PBAs)are prepared by a precipitation method with Co^(2+)and[Fe(CN)_(6)]^(3−),which experience a structural conversion from nanocubes to NFs by increasing the aging temperature from 5 to 35℃.The experimental results indicate that this conversion is attributable to the preferentially epitaxial growth on the edges and corners of nanocubes,triggered by intramolecular electron transfer at an elevated aging temperature.The as-prepared Co-Fe-P NFs catalyst shows remarkable catalytic activity toward OER with a low overpotential of 276 mV to obtain a current density of 10 mA cm^(−2),which is superior to the reference samples(Co-Fe-P nanocubes)and most of the recently reported TMPs-based electrocatalysts.The synthetic strategy can be extended to fabricate Co-Fe dichalcogenide NFs,thereby holding a great promise for the broad applications in energy storage and conversion systems.
文摘In step with reform and opening up, the Chinese system of anti-corruption charges has been progressively refined and elaborated. Its successive refinements and comprehensive transformation have resulted in a tight-knit network of anti-corruption criminal law and a dual system of charges. This system has made a remarkable contribution to combating corruption over the last three decades. More than the outcome of the natural evolution of legal logic, it also involves complex considerations of social transformation and reflects lawmakers＇ expectations of being able to prevent corruption at the institutional level. With the deepening and widening of reform and opening up, China＇s system of anti-corruption charges will inevitably develop towards the thorough abolition of the dual system of charges and the complete restoration of the unitary system.
