H2S is a toxic and corrosive gas which is detrimental for both human’s health and some of important industries such as oil and gas. Based on different experimental research among various systems, resistive sensors fabricated from SnO2-CuO nanostructures have promising performance toward detection of this gas. High sensitivity and selectivity, response time of order of seconds, recovery times of order of tens of seconds and determining concentration of H2S gas below ppm level are advantages of this system. Unfortunately due to lack of a theoretical model, current experimental researches are excessively based on “trial and error” methodology. In this research some of the basic questions which...