A low-cost and large-scale synthesis of nano-zinc oxide from smithsonite
Nano-zinc oxide was prepared through a series of complex chemical reactions from smithsonite ores and the sensitivity of products to alcohol was measured. The smithsonite ores were calcined and decomposed into ZnO at 400 C, and then were leached by sodium hydroxide solution. The leaching solution was purified by adding sodium sulfide, and the amount ratio of lead removal agent to lead ions (Na2S·9H2O/Pb) was 4.37. The zinc ions were precipitated in the form of Zn(OH)2(s) by regulating the pH. Finally, the precipitate was calcined in muffle furnace at 500 C and decomposed into nano-ZnO. The optimum operating temperature of sensitivity to alcohol was 160 C, and the sensitivity of the products with polyethylene glycol (PEG) rose at lower temperature and attained higher maximum value than that of the product without PEG. Especially, the sensitivity of ZnO prepared with 3 wt.% PEG to alcohol could be about 35 at 160 C.