Anodic and cathodic process of hypophosphite on a Ni-Ag electrode

• 来源期刊: 中国化学(英文版)
• 年，卷（期）: 2000,（5）
• 页码范围: 703-709
• 页数: 7页
• 语种: 英文

摘要

The reduction and the oxidation of hypophosphite on a Ni-Ag electrode have been studied to provide the information about the phosphorus incorporation mechanisms during the electro less deposition and the electrodeposition of Ni-P alloys. In the electrooxidation process, an absorbency band around 240 nm, which was ascribed to the formation of an intermediate 'PHO2-, was observed by in situ UV-Vis subtractive re flectance spectroscopy. Accordingly, the electrooxidation of hypophosphite might undergo an H abstraction of hypophos phite from the P－H bond to form the phosphorus-centred radical ' PHO2-, which was subsequently electrooxidized to the final product, phosohite. In the reduction process Ni-phos phine compound Ni-(PH3)n was observed by in situ surface P-aman spectroscopy. The results from the Raman experi ments show that, in the NiSO4-free solution, hypophosphite was reduced only to Ni-phosphine compound, while in the case where NiSO4 coexisted in the solutions, the Ni-phosphine compound, as an intermediate, was oxidised by Ni2 + to ele mental phosphorus in alloys with nickel acting as the catalyst.