다공성 탄소전극상 무전해 니켈도금의 산성과 알칼리용액 비교 연구

Abstract

Electroless nickel plating on porous carbon substrate for the application of MCFC electrodes was investigated. Acidic and alkaline bath were used for the electroless nickel plating. The pore sizes of carbon substrates were 16-20 μm and over 20 μm. The carbon surface was changed from hydrophobic to hydrophilic after immersing the substrate in an ammonia solution for 40 min at 60℃. The contact angle of water was decreased from 85˚ to less than 20˚ after ammonia pretreatment. The deposition rate in the alkaline bath was higher than that in the acidic bath. The deposition rate was increased with increasing pH in both acidic and alkaline bath. The content of phosphorous in nickel deposit was decreased with increasing pH in both acidic and alkaline bath. The contents of phosphorous is low in alkaline bath. The minimum concentration of PdCl2 for the electroless nickel plating was 10 ppm in alkaline bath and 5ppm in acidic bath. The thickness of nickel was not affected by the concentration of PdCl2.