Abstract

This mini review focuses on the application of N and P‐type metal oxides semiconductor thin films, such as TiO₂, SnO₂, CO₃O₄ and Mn₃O₄, used in air pollution for NO₂ and H₂S gas sensing applications. Metal Oxide thin films exhibit several advantages including a higher catalytic effect, low humidity dependence, and improved performance. However, the sensing performance of metal oxide thin films is strongly related to their intrinsic physicochemical properties of the materials. A review of each comparison, as well as metal oxide that has the high gas sensitivity in the recent years. Future trends to overcome the challenges of metal oxide semiconductors gas sensors are also presented.

Keywords: Metal oxide; Semiconductors; Thin films; Air pollution; Gas sensors