碳纳米颗粒掺杂过渡金属磷化物的制备及其析氢性能研究

Preparation and hydrogen evolution performance of carbon nanoparticles-doped transition metal phosphides

目的过渡金属因其优异的电催化性能被广泛研究,然而过渡金属磷化物较差的析氢活性和在酸中的不稳定性阻碍了其进一步应用。碳纳米颗粒(CNPs)具有低成本、制备工艺简单、高稳定性和高导电性等优点,可以通过添加碳材料对过渡金属磷化物的结构进行有效调控,从而提高材料的析氢活性和稳定性。方法以葡萄糖为碳源制备了富含羟基和羧基官能团的碳纳米颗粒(P-CNPs),以具有高比表面积的泡沫镍为基底,通过水热法制备掺杂P-CNPs的NiCo前驱体,再经过磷化反应得到掺杂P-CNPs的过渡金属磷化物NiCoP-PC/NF。结果在0.5 mol/L H_(2)SO_(4)和1 mol/L KOH中的阴极极化曲线表明,在电流密度10 mA/cm^(2)、碳纳米颗粒浓度50 mg/L时,NiCoP-50PC/NC的过电位分别低至59 mV和90 mV,均远小于商业Pt/C;同时,NiCoP-50PC/NF在0.5 mol/L H_(2)SO_(4)和1 mol/L KOH中的阴极极化曲线几乎重合,表明析氢活性没有发生明显的衰减,具有良好的电化学稳定性。结论碳纳米颗粒掺杂方法为提高过渡金属材料析氢性能提供了一种新的思路。

Objective Transition metals have been widely studied due to their excellent electrocatalytic properties.However,the poor hydrogen evolution activity and instability of transition metal phosphides in acid hinder their further application.Carbon nanoparticles(CNPs)have several advantages of low cost,simple preparation process,high stability and high electrical conductivity.The structure of transition metal phosphide can be effectively regulated by adding carbon material to improve the hydrogen evolution activity and stability.Methods Carbon nanoparticles rich in hydroxyl and carboxyl functional groups(P-CNPs)were prepared using glucose as carbon source.P-CNPs-doped NiCo precursor was prepared by hydrothermal method using nickel foam with high specific surface area as substrate.After phosphating reaction,P-CNPs-doped NiCoP-PC/NF was obtained.Results The cathodic polarization curves in 0.5 mol/L H_(2)SO_(4) and 1 mol/L KOH showed that the overpotential of NiCoP-50PC/NF was as low as 59 mV and 90 mV at 10 mA/cm^(2) of current density and 50 mg/L of carbon nanoparticles concentration,respectively,which were much lower than that of commercial Pt/C.Moreover,the cathodic polarization curves of NiCoP-50PC/NC in 0.5 mol/L H_(2)SO_(4) and 1 mol/L KOH almost coincide,indicating that there is no obvious attenuation of hydrogen evolution activity,and the NiCoP-50PC/NC has good electrochemical stability.Conclusion The method of doping carbon nanoparticles provides a new way to improve the hydrogen evolution performance of transition metal materials.