Facile synthesis of V-doped CoP nanoparticles as bifunctional electrocatalyst for efficient water splitting

Adjusting the intrinsic activity and conductivity of electrocatalysts may be a crucial way for excellent performance for water splitting.Herein,the rational design of vanadium element doped cobalt phosphide(V-doped CoP)nanoparticles has been investigated through a facile gaseous phosphorization using cobalt vanadium oxide or hydroxide(Co-V hydr(oxy)oxide)as precursor.The physical characterization shows that the homogeneous dispersion of V element on V-doped CoP nanoparticles have obtained,which may imply the enhanced electrocatalytic activity for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).The electrochemical measurements of the prepared V-doped CoP in alkaline electrolyte demonstrate the superior electrocatalytic activity for both HER(overpotential of 235 mV@10 mA cm^-2)and OER(overpotential of 340 mV@10 mA cm^-2).Further,V-doped CoP nanoparticles used as anode and cathode simultaneously in a cell require only 370 mV to achieve a current density of 10 mA cm^-2.The outstanding electrocatalytic activity may be ascribed to the improved conductivity and intrinsic activity owing to phosphating and the doping of V element.In addition,the long-term stability of V-doped Co P has been obtained.Therefore,metal doping into transition metal-based phosphides may be a promising strategy for the remarkable bifunctional electrocatalyst for water splitting.

原位构筑表面缺陷的碳掺杂型三元钴镍铁磷化物纳米立方体用于高效全水分解（英文）

本文以三元金属钴-镍-铁普鲁士蓝结构纳米立方体(Co0.9-Ni0.9Fe1.2NCs)为前驱体,通过简单气相磷化处理,得到优化比例的P-Co0.9Ni0.9Fe1.2纳米立方体磷化物,其具有高本征活性、导电性和高缺陷密度的特点. SEM和TEM结果表明,碳掺杂型P-Co0.9Ni0.9-Fe1.2保持了纳米立方体的结构,其粗糙的表面结构意味着丰富的缺陷位,暴露更多真实活性位.三元金属普鲁士蓝前驱体的磷化处理不仅提供了碳掺杂,而且原位构筑了立方体表面缺陷位.碳掺杂降低了电荷传输的阻抗,优化了电子传输速率.三元金属离子之间的协同作用以及丰富的缺陷活性位有效提高了电催化的性能.P-Co0.9Ni0.9Fe1.2拥有极其高的HER和OER催化活性,仅需要-200.7 mV(HER)和273.1 mV(OER)过电位就可以达到10 mA cm-2的电流密度.其全水分解仅需1.52 V就可以达到10 mA cm-2的电流密度.此外,本文还对催化剂的稳定性进行了测试.本工作为设计高效过渡金属基双功能电解水催化剂提供了一种简便方法.