摘要
采用高温熔融法在Sb_(12)Ge_(28)Se_(60)玻璃中掺0～2%(at)铁,电导率增加7个数量级。根据ESR的测定结果,电导率激增是由于铁在玻璃能隙中形成了Fe^(2+)(d^6)施主能级。用掺铁玻璃制成了对Fe^(3+)离子在10^(-5)～10^(-1)mol/L浓度范围线性响应斜率为58.3 mV/mol·L^(-1)的电极。该电极在强酸性溶液中十分稳定。根据半导体玻璃的能带模型以及XPS的实验结果,提出了该硫系玻璃电极的选择性响应机理。
0～2%(at) iron was doped into the Sb_(12)Ge_(28)Se_(60) chalcogenide glasses by a melting method. The conductivity increases 7 orders of magnitude after the addition of iron. The analyses of ESR indicated that the doped iron forms a Fe_(2+)(d^6) donor level in the glass band gap, this donor level causes the rapid increase of conductivity. By using the iron-doped glasses, the Fe^(3+) ion-selective electrodes were prepared. These electrodes show Nernstian response to Fe^(3+) ions in 10^(-5)～10^(-1) mol/L with the slope of about 58.3 mV/mol·L^(-1) and are very stable in strong acid solutions. Based on the models of energy band structure of the semiconductor glasses and the results of XPS, the mechanism of ion-selective response of the glass electrodes was proposed.
关键词
掺铁
硫系
玻璃电极
离子选择电极
chalcogenide glass semiconductors
ion-selective electrode
electrochemical analysis
glass electrode
energy band structure
