New Process of Palladium Electroplating Form Potassium Citrate Bath

研究在柠檬酸钾和草酸铵镀液体系中镀钯工艺。结果表明，采用本实验室研制的添加剂XP-4和XP-7以及PPS和ff，则可在电流密度0.5~3.5A/dM2、温度40~60℃的宽范围内获得全光亮的钯电沉积层。钯沉积的电流效率和沉积速度在镀液中钯含量为10g/l、1.0A/dM2的条件下分别可达到92.0%和0.25μM/MIn，并随电流密度和镀液中钯含量的变化而改变。XP-4和XP-7均阻化钯的电沉积，提高钯电沉积的过电位。它们共存时可使把电沉积的电位负移达240MV。Process of Pd plating From system of potassium citrate and ammonium oxalate is investigated.Results show, with additives of XP-4, XP-7, PPS and FF prepared in our laboratory, Full bright Pd electrodeposit can be obtained in wide range of 0.5-3.5 A/dm2 and 4a-60℃ and at 1.0 A/dm2 and Pd 10 g/L contg in bath, current eFFiciency and deposition rate are 92.0% and 0.25μm/min respectively,which will be changed with change of c.d.and Pd content in bath.Both XP-4 and XP-7 inhibit Pd electrodeposition and cause increase of deposition overpotential.Their co existence can make Pd electrodeposition potential shiFt to negative value, up to 240mV

碳化法纳米SiO_2表面结构研究

采用红外、热重、N2吸附等分析方法,研究了碳化法制备的纳米Si O2表面羟基、孔隙结构和吸油值等随陈化p H值、陈化时间及干燥温度的变化关系。实验结果表明,在不同陈化p H值下Si O2凝聚反应速率不同,陈化p H值由2升高到5,凝聚反应加快,颗粒表面羟基含量由1.54个/nm2减少到1.44个/nm2,平均孔径由11.51 nm增大到23.06 nm,吸油值由1.70 cm3/g升高到1.81 cm3/g;在不同陈化时间下Si O2颗粒间凝聚反应进程不同,陈化时间由10 min延长到90 min,颗粒表面羟基含量由1.48个/nm2减少到1.40个/nm2,平均孔径、吸油值变化不明显;在不同...</p

碳化法纳米 SiO_2表面结构研究

采用红外、热重、N2吸附等分析方法,研究了碳化法制备的纳米Si O2表面羟基、孔隙结构和吸油值等随陈化p H值、陈化时间及干燥温度的变化关系。实验结果表明,在不同陈化p H值下Si O2凝聚反应速率不同,陈化p H值由2升高到5,凝聚反应加快,颗粒表面羟基含量由1.54个/nm2减少到1.44个/nm2,平均孔径由11.51 nm增大到23.06 nm,吸油值由1.70 cm3/g升高到1.81 cm3/g;在不同陈化时间下Si O2颗粒间凝聚反应进程不同,陈化时间由10 min延长到90 min,颗粒表面羟基含量由1.48个/nm2减少到1.40个/nm2,平均孔径、吸油值变化不明显;在不同..

碳化法纳米SiO_2表面结构研究

采用红外、热重、N2吸附等分析方法,研究了碳化法制备的纳米Si O2表面羟基、孔隙结构和吸油值等随陈化p H值、陈化时间及干燥温度的变化关系。实验结果表明,在不同陈化p H值下Si O2凝聚反应速率不同,陈化p H值由2升高到5,凝聚反应加快,颗粒表面羟基含量由1.54个/nm2减少到1.44个/nm2,平均孔径由11.51 nm增大到23.06 nm,吸油值由1.70 cm3/g升高到1.81 cm3/g;在不同陈化时间下Si O2颗粒间凝聚反应进程不同,陈化时间由10 min延长到90 min,颗粒表面羟基含量由1.48个/nm2减少到1.40个/nm2,平均孔径、吸油值变化不明显;在不同..

A Study on the Electrodeposition of Palladium and it′s Nucleation

研究在柠檬酸钾和草酸铵镀液体系中纯钯电沉积及电结晶机理．结果表明，采用本实验室研制的添加剂②ＸＰ－４和ＸＰ－７，可在电流密度０．５～３．５Ａ／ｄｍ２，温度４０～６０℃的宽广范围内获得全光亮的钯电沉积积层．采用脉冲电源电镀可有效地改善厚沉积层质量，减少沉积层裂纹和孔洞．循环伏安实验表明，钯电极过程的阴阳极峰电位之差达１．０５Ｖ，说明其电极过程明显不可逆；伏安图上同时出现一感抗性电流环，说明钯沉积过程发生晶核形成过程；ＸＰ－４和ＸＰ－７阻化电沉积和氢的析出，提高钯电沉积的沉积电位．电位阶跃实验进一步表明，钯遵循连续成核和三－维生长的电结晶机理．The electrodeposition and nucleation of palladium are studied in the system of potassium citrate and ammonium oxalate. The results show that, with the additives of XP 4 and XP 7 prepared in our laboratory, a full bright palladium electrodeposits will be obtained in the wide ranges of the cathode current densities 0.5～3.5 A/dm 2 and temperature 40～60 ℃; the qualities of the thick deposits will be effectively improved by means of pulse current plating. Cyclic voltammograms results show that the division of peaks between anodic and cathodic on the electrode process of palladium will be up to 1.05 V, which shows the irreversible electrode process; and a inductive current cycle is appeared,which means the process of nucleation; XP 4 and XP 7 inhibit both palladium electrodeposition and hydrogen evolution, therefore cause the deposition potential of palladium to more negative; potential step experiments furtherly show that the nucleation of palladium obeyed progressive uncleation mechanism both with the studied additives or without them.作者联系地址：厦门大学化学系物理化学研究所Author's Address: Chem. Dept., Insti of Phys. Chem. Xiamen Univ., Xiamen 36100