Because of high sensitivity, short response time, small size and light weight, metal oxide based gas-sensors are extensively applied in many fields, such as chemistry-engineering, coal mine exploiting, environment conservation, agriculture development and health for detecting poisonous and flammable gas to avoid possible accident.However, SnO_2 is widely-used sensing material and easily affected by the change of operating temperature and humidity, so the long-term sensitivity and stability become worse and ...