A Review on Chemiresistive Hybrid Zinc Oxide and Nanocomposites for Gas Sensing

Chemiresistors have been widely employedin monitoring toxic fumes,gases, and environmental pollutants. Among a plethora of metal oxidesemiconductors (MOX) used for preparing chemiresistors, zinc oxideis the topmost candidate. ZnO-based gas sensors are cost-effective,nontoxic, stable, and easily prepared by wet chemical facile approaches.ZnO nanostructures are the most promising candidates for leakage detectionof toxic gases with reliable performance. In this regard, severalinvestigations have been carried out to increase sensor response atroom temperature (RT). Current advances in ZnO nanostructures-basedthin films are the subject of this review paper. The review beginswith a basic survey of ZnO thin films for gas sensors focusing onhow the structure and properties of ZnO affect the gas response mechanisms,various factors and processing methods of ZnO nanostructures, andpossible ways to enhance the gas response characteristics of ZnO-basedsensors.