The preparation and gas sensitivity study of polypyrrole/zinc oxide

Polypyrrole (PPy) was prepared by chemical oxidation polymerization, analyzed by FT-IR, elemental analysis and HRTEM, and studied for gas sensitivity. It suggested that PPy had sensitivity to NH 3 , H 2 S and NO x , and showed irreversibility to NO x gas. The organic–inorganic hybrid materials PPy/ZnO with different PPy weight percents were prepared by mechanical mixing, and the sensitivity study of the materials to toxic gases NH 3 , H 2 S, NO x was carried out at different operating temperatures 30, 60, and 90 °C. It was found that PPy/ZnO materials (PPy(1%)/ZnO, PPy(3%)/ZnO, PPy(5%)/ZnO, PPy(10%)/ZnO, PPy(20%)/ZnO) had better selectivity and reversibility to NO x than pure PPy, and much lower working temperature than the reported working temperature of ZnO (about 350–450 °C). Their sensitivity increased with the increasing concentration of NO x at particular working temperature, and among them PPy(10%)/ZnO had the maximum sensitivity to NO x in the same condition. They showed no response to 1000, 1500, 2000 ppm NH 3 or H 2 S. The response mechanism of PPy/ZnO materials to NO x was discussed.