共掺杂三维石墨烯的制备及其电催化析氢性能的研究

选择天然石墨鳞片为原料,采用改进的Hummers法制备出氧化石墨(GO),再以硫脲、硫酸亚铁和氯化镍为改性剂,利用化学还原法和自组装法制备了氮、硫、铁、镍共掺杂三维石墨烯电极材料。通过扫描电子显微镜(SEM)、X射线衍射(XRD)、X射线能谱(EDS)等测试手段对材料进行分析表征,研究了不同因素对其析氢反应活性(HER)的影响,并通过均匀试验设计确定了制备的最佳工艺条件。结果表明:所制备的电极材料具有丰富的孔结构和完整的三维结构,石墨烯片层间距为0.3734 nm,并且无明显垛叠团聚,在酸性条件下显示出较高的HER活性,在电流密度为10 mA/cm2时,析氢过电位为-158 mV,塔菲尔(Tafel)斜率为74.33 mV/dec。

Preparation of co-doped three-dimensional graphene and its electrocatalytic hydrogen evolution performance

The co-doping three-dimensional graphene electrode material was prepared by chemical reduction method and self-assembly method using thiourea,ethylene iron sulfate and nickel chloride as modifier,while the graphite oxide was prepared by modified Hummers method using natural graphite flakes as the raw material.The materials were analyzed and characterized by SEM,XRD and EDS.The effects of different factors on the hydrogen evolution reaction(HER)were studied and the optimal process conditions were determined by uniform experimental design.The results show that the obtained samples had extensive pore structure and complete three-dimensional structure of the graphene sheet spacing of 0.3734 nm,and no significant agglomeration stacked pile.It showed higher HER activity under acidic conditions.At a current density of 10 mA/cm2,the hydrogen evolution overpotential was-158 mV and the Tafel slope was 74.33 mV/dec.