射频磁控溅射制备纳米晶Ni-Mo催化阴极及其表征

Preparation and Characterization of Nanocrystalline Ni-Mo as Cathode Catalyst via RF Magnetron Sputtering

利用射频磁控溅射方法制备了纳米晶N i-Mo合金薄膜,并将其用作太阳能光电化学制氢的阴极催化膜.采用XRD,EDS,SEM和AFM对膜的晶型、成分、表面形貌以及晶粒尺寸进行了表征.用稳态极化曲线和电化学交流阻抗谱对膜的析氢电化学特性进行了测试.结果表明,在较高的工作压强、较低的衬底温度和较远的靶距下沉积的膜有较好的电化学性能,晶粒的细化以及膜中Mo含量的增加有助于析氢催化活性的提高,在电流密度为100 mA/cm2时析氢过电势为177.7 mV,电化学脱附是膜上析氢反应的控制步骤.

Ni-Mo alloy thin film was prepared by RF magnetron sputtering method, and the film was used as cathode catalyst in photoelectrochemical hydrogen production from solar energy firstly. The crystallinity, composition, surface morphology and crystalline size were characterized by XRD, EDS, SEM and AFM experi- ments. The electrochemical behavior of the film were studied chemical impedance spectroscopy. The results mentioned abov by steady-state e show that und working pressure, lower substrate temperature and the longer target distance the polarization plots and electroer the conditions of the higher Ni-Mo alloy thin film obtained possesses a good electrocatalytic activity. Additionally, the electrocatalytic activity of the film was also enhanced with the decreasing of crystalline size and increasing of molybdenum content. The hydrogen overpotential of hydrogen evolution reaction is 177.7 mV at current density 100 mA/cm^2. The rate-limiting step was electrochemical desorption.