V掺杂Co_(4)N的双功能型电解水催化剂的设计与制备

Rational Design and Fabrication of V-doped Co_(4)N as Bifunctional Electrocatalyst for Water Splitting

为考察V掺杂Co_(4)N的电解水催化性能,通过一步水热法合成含有Co/V的双金属氢氧化物前驱体CoV-LDH,并以尿素作为氮源,通过化学气相沉积法促使CoV-LDH向其氮化物结构实现相转变,从而获得钒掺杂的氮化四钴V-Co_(4)N,该材料表现为由三维泡沫镍支撑的二维纳米片阵列结构。通过电化学法研究了V-Co_(4)N的电解水催化特性,实验表明所得目标结构具有双功能型电解水催化特性,当驱动电流密度为10 mA/cm2时,其阴极端和阳极端所需过电势分别为61 mV和245 mV,相较于现有商用催化剂具备较强的竞争优势。进一步横向对比研究了引入Mo、Mn、Cr不同金属掺杂,不同热处理温度以及不同阴离子配位的因素对目标结构的电催化活性的影响。结果表明:引入V掺杂,N作为钴阴离子配位,且采用350℃热处理所得目标产物具有最佳催化活性和经济效应。

In order to investigate the catalytic performance of V-doped Co_(4)N in electrolyzed water,the Co/V-containing layered double hydroxide precursor of CoV-LDH was synthesized by a one-step hydrothermal method,then urea served as the nitrogen source to promote CoV-LDH phase transition to its nitride structure through chemical vapor deposition.As result,the vanadium-doped cobalt nitride V-Co_(4)N was obtained.The structure appears as a two-dimensional nanosheet array structure which supported by three-dimensional nickel foam.The electrochemical method was used to study the catalytic properties of V-Co_(4)N in electrolyzed water.The target structure shown bifunctional electrolytic water catalytic properties.When to drive the current density of 10 mA/cm2,the required overpotential of the cathode and anode sections were 61 mV and 245 mV,respectively.Compared to that of commercial catalysts,it has a strong competitive advantage.Furthermore,the influence of the introduction of Mo、Mn and Cr with different metal doping,different heat treatment temperatures and different anion coordination factors on the electrocatalytic activity of the target structure were also further studied.The results shown that the V doping,N as the coordination,and the heat treatment temperature of 350℃were the proper choices to adjust the best catalytic activity and economic effect.