WU Jing, LI Yan, QIN Shan, LU An-huai

（Key Laboratory of Orogenic Belts and Crustal Evolution of MOE, Department of Geology, Peking University, Beijing 100871, China）

Abstract：In-situ high temperature X-ray diffraction study was carried out on the natural sphalerite. The results showed that sphalerite expanded with the increasing temperature and its volume thermal expansion coefficient was 25.61×10-6℃-1 in the range of 27～675℃. During the heating, an intermediate phase Zn3O(SO4)2 was observed at 543℃, then decomposed into zincite ZnO. The complete breakdown of Zn3O(SO4)2 happened at 797℃, accompanied by the formation of ZnFe2O4 which had a spinel structure. At 1160℃, ZnO coexisted with ZnFe2O4. The experiment revealed that heat treatment of natural sphalerite could lead to the formation of a certain proportion zincite (ZnO), which could compose a binary compound semiconductor together with sphalerite. When the compound semiconductor system was excited by certain light source, the photo-induced carrier would transfer from one semiconductor particle to the other, reducing the combination of photo-induced electron-hole pairs, which could improve the photocatalytic activity of the system. This work could be theoretically helpful in the field of enhancing the photocatalytic abilities of natural sphalerite using heat treatment.

Key words：natural sphalerite; in-situ high temperature XRD; ZnO; compound semiconductor; photocatalytic activity

E-mail: liyan-pku@163.com

ACTA MINERALOGICA SINICA Vol. 31, No. 4, 2011, Page 647-653