The effect of polarization time on the schiff base self assembled monolayer containing hydrosulfo group has been investigated by CV and ac impedance measurements. The results showed that, when the potential of -0 87 V...The effect of polarization time on the schiff base self assembled monolayer containing hydrosulfo group has been investigated by CV and ac impedance measurements. The results showed that, when the potential of -0 87 V( vs .SCE) was applied on the monolayer, the electrochemical charge transfer resistance R ct originated from the reduction of CN increased with the polarization time within 4 min and then decreased. This phenomenon may be related to the relationship between the CN group and the structure of the Schiff base self assembled monolayer.展开更多
通电电流密度及极化时间对Ag/AgCl电极性能影响较大,其取值争议较大。将Ag棒放入0.1 mol/L的HCl溶液中进行电解,电流密度为0.5,1.0,2.0,3.0,4.0 m A/cm^2,通电时间为0.5,1.0,1.5,2.0,2.5,3.0 h。在电极电解过程中,记录电位-时间曲线。通...通电电流密度及极化时间对Ag/AgCl电极性能影响较大,其取值争议较大。将Ag棒放入0.1 mol/L的HCl溶液中进行电解,电流密度为0.5,1.0,2.0,3.0,4.0 m A/cm^2,通电时间为0.5,1.0,1.5,2.0,2.5,3.0 h。在电极电解过程中,记录电位-时间曲线。通过SEM观察不同条件所得电极的表面形貌,并用EDS分析其元素组成。结果表明:随着极化时间的增长,Ag棒表面电解产物增多,在恒定通电电流密度条件下,电解产物的生成增大了电极的电阻,从而导致电极电位随极化时间的增长而增大;极化时间相同时,通电电流密度越大,电解产物生成速度越快,电极电位越高,多层电解产物的穿插生成导致电极表面粗糙,并伴有小坑等缺陷出现;电解产物主要由Ag和Cl组成;当电流密度小于或等于1.0 m A/cm^2时,电极电位增长缓慢,电解产物缓慢生长,电极表面较为致密,通电电流密度为0.5 m A/cm^2的电极电位在9 800 s左右出现骤降,为获得较为致密和性能稳定的Ag/AgCl电极,建议阳极极化法制备Ag/AgCl电极的通电电流密度为0.5 m A/cm^2,极化时间为2.5 h(9 000 s)。展开更多
文摘The effect of polarization time on the schiff base self assembled monolayer containing hydrosulfo group has been investigated by CV and ac impedance measurements. The results showed that, when the potential of -0 87 V( vs .SCE) was applied on the monolayer, the electrochemical charge transfer resistance R ct originated from the reduction of CN increased with the polarization time within 4 min and then decreased. This phenomenon may be related to the relationship between the CN group and the structure of the Schiff base self assembled monolayer.
文摘通电电流密度及极化时间对Ag/AgCl电极性能影响较大,其取值争议较大。将Ag棒放入0.1 mol/L的HCl溶液中进行电解,电流密度为0.5,1.0,2.0,3.0,4.0 m A/cm^2,通电时间为0.5,1.0,1.5,2.0,2.5,3.0 h。在电极电解过程中,记录电位-时间曲线。通过SEM观察不同条件所得电极的表面形貌,并用EDS分析其元素组成。结果表明:随着极化时间的增长,Ag棒表面电解产物增多,在恒定通电电流密度条件下,电解产物的生成增大了电极的电阻,从而导致电极电位随极化时间的增长而增大;极化时间相同时,通电电流密度越大,电解产物生成速度越快,电极电位越高,多层电解产物的穿插生成导致电极表面粗糙,并伴有小坑等缺陷出现;电解产物主要由Ag和Cl组成;当电流密度小于或等于1.0 m A/cm^2时,电极电位增长缓慢,电解产物缓慢生长,电极表面较为致密,通电电流密度为0.5 m A/cm^2的电极电位在9 800 s左右出现骤降,为获得较为致密和性能稳定的Ag/AgCl电极,建议阳极极化法制备Ag/AgCl电极的通电电流密度为0.5 m A/cm^2,极化时间为2.5 h(9 000 s)。
