摘要
用溶胶—凝胶盐酸催化法成功制备纳米SiO2 溶胶 ,并用浸镀法在经过超声的载玻片上制得SiO2 薄膜。将薄膜浸入氯化钯、氯化铜混合溶液 ,匀速提拉 ,干燥后制得敏感膜 ,利用钯盐与CO反应 ,生成钯单质 ,引起吸光度变化。在 5 10nm波长下 ,测量吸光度的变化 ,在 2 0min内 ,吸光度的变化随着CO气体浓度的增加而增加。实验表明 ,基于 3倍信噪比 ,可估算出该敏感膜检测极限为 18× 10 - 6 (体积分数 ,下同 ) ,完全可用于 6× 10 - 4CO气体临界报警浓度的检测 ,而氯化铜能在空气中将钯氧化成钯盐 ,该敏感膜可反复使用 ,空气中还原时间为 4d。用一些家庭常见的易挥发有机溶剂所做的干扰实验表明 。
Silicon dioxide thin film prepared by a sol-gel technique is used as a sensing layer after treatment of solution of palladium chloride and copper chloride for the reduction of Pd 2+ ions by CO gas which causes the change of layer absorbence. With photocurrent measurement at 510nm wave length, an obvious photocurrent response is observed for 6×10 -4 CO gas in comparision with the blank sample. It can be expected that, the present sensing layer can detect the concentration of CO gas below 18×10 -6 based on three times of signal tonoise. The sensing layer can be recovered through copper oxidizing Pd. The recovery time of the thin layer is four days in dry air. Interferential experiment shows that, no obvious response is found for the organic odor in living surroundings.
出处
《河南化工》
CAS
2003年第11期12-14,共3页
Henan Chemical Industry
