p型Si(100)化学镀NiP薄膜的制备及性能研究

Electroless Deposition of NiP Film on p-Si(100) and Its Property Study

采用化学镀的方法在组成为NiSO4.6H2O+NaH2PO2.H2O+Na3C6H5O7.H2O的化学镀液中与Pd活化的p型Si(100)表面制备了NiP薄膜,利用X射线能量色散谱(EDX)对NiP薄膜的成分进行了表征。用原子力显微镜(AFM)和电化学阳极溶出(ASV)的方法对不同化学镀时间下的NiP薄膜在Si表面的覆盖度进行了研究。结果表明,在表面覆盖度Γ达到4.03×10-8mol/cm2时,表面覆盖达到饱和,此时颗粒大小均一,并分布均匀。以NiP/Si为工作电极,在0.5 mol/L1的H2SO4溶液中分别在光照和暗态条件下对不同化学镀时间的NiP薄膜进行阴极极化扫描,结果表明,在Si表面未完全被覆盖和过度被覆盖的情况下光电催化的性能都没有达到最高,仅当Si表面被完全覆盖时,具有最强的光电催化析氢特性。

The NiP films are electrolessly plated on the p-Si（100） surface in the bath of NiSO4 · 6H2O＋ NaH2PO2 · H2O＋Na3C6H5O7 · H2O at the temperature of （90±2） ℃ based on the palladium as catalytic seed layer. The seed layer is deposited on the silicon surface by introducing silicon wafer in solution of SnSO4 firstly and then in PdCl2 in consequence. The composition of the films is characterized by energy dispersive X ray analysis （EDX）, the morphology and the surface coverage of the NiP film are investigated by atomic force microcopy （AFM） and anodic stripping sweep votammetry （ASV）. The result show that the silicon surface is just fully covered by uniform and even NiP particles with the surface coverage （Г） reaching 4.03 × 10^-8 mol/cm^2. The cathodic polarization curves for hydrogen evolution under illumination and in dark are detected in 0. 5 mol · L^-1 H2SO4 solution with the working electrode of NiP/Si at different deposition time. The result show that NiP/Si electrode has the most efficient photocatalytic hydrogen evolution activity when the silicon surface is properly covered by NiP film.