磷化钴/碳纳米管纳米复合电极材料的电催化制氢性能研究

Electrocatalytic performance of CoP/CNTs nanocomposite electrodes for hydrogen evolution

采用化学气相沉积法,在316L不锈钢基底上原位生长碳纳米管,然后在一定浓度的CoSO_4、NaH_2PO_2、NaOAc混合溶液中,用电化学沉积法在碳纳米管表面负载磷化钴纳米颗粒,得到磷化钴/碳纳米管复合结构。利用SEM、EDS和拉曼光谱,对CoP/CNTs复合材料的形貌、成分及物相组成进行分析;通过阴极极化曲线、交流阻抗等电化学测试,重点考察了复合电极在0.5mol/L H_2SO_4溶液中的电催化析氢性能。结果表明,所制CoP/CNTs复合结构中,CoP呈颗粒状均匀分布在CNTs表面;CoP的引入提高了碳纳米管材料的电催化性能,当沉积圈数为4圈时,所制CoP/CNTs复合电极具有最佳的电催化活性;极化曲线测试表明,该电极在电流密度为10mV·cm^(-2)时的过电位与沉积2圈和6圈的CoP/CNTs复合电极相比,正移了约140 mV和90mV,同时也呈现出良好的循环稳定性。

Carbon nanotubes（CNTs）were fabricated directly on 316 Lstainless steel substrates by chemical vapor deposition,and then electro-deposition method is adopted to carry cobalt phosphate nanoparticles with the mixed solution of CoSO_4,NaH_2PO_2 and NaOAc as the electrolyte.The morphoploy,microstructure and phase composition of the CoP/CNTs nanocomposites were characteriazed with the aid of SEM,EDS and Raman specrum,and the electrocatalytic activity for hydrogen evolution of the prepared electrodes in 0.5 mol/L H_2SO_4 solution was studied by means of cathodic polarization curves and AC impedance technique.The results show that in the prepared CoP/CNT nanostructure,CoP particles are uniformly distributed on the surface of CNTs,and the catalytic performance of CNTs can be promoted due to the introduction of CoP.CoP/CNTs composite electrode perpared by 4 cycles of cyclic sweep exhibits the optimum electrocatalytic performance and cycling stability for hydrogen evolution,and the polarization curves indicate that the overpotential of this electrode positively shifts about 140 mV and 90 mV at the current density of 10 mA·cm^（-2）,compared with the CoP/CNTs electrodes deposited by 2 cycles and 6 cycles,respectively.