FACTORS CAUSING DIFFERENT CODEPOSITION CONTENTS OF Cr AND Al NANOPARTICLES DURING Ni ELECTRODEPOSITION
影响共电沉积过程中纳米Cr、Al粒子复合量因素初探

It was found that Al nanoparticles were easier to be codeposited than Cr nanoparticles during co - electrodeposition of nickel with nanoparticles of Al or Cr. The cathodic polarization test shows that the codeposition of Ni-Cr nanoparticles reduced the cathodic polarization, however, a reverse result was obtained during the codeposition of Ni-Al nanoparticles. HREM investigation indicated the existance of a 3 - 5 nm Cr2O3 or Al2O3 film on the surface of Cr and Al particles respectively. It is proposed that the Cr2O3 film is a p - type semiconductor, which exhibits a weak adsorption of cations during codeposition, while the Al2O3 film is a n - type semiconductor, which has a strong adsorption of cations of nickel and hydrogen. The different adsorption ability of the two oxide films formed is the primary factor causing the various codeposition contents of Cr and Al nanoparticles.