Resistive-Based Nanostructured CeO₂ Gas Sensors: A Review

Air pollution and the emission of toxic gases represent a critical global concern, posing significant threats to human health and environmental stability. Resistive gas sensors are widely employed to detect toxic gases, owing to their cost-effectiveness, high stability, sensitivity, and swift dynamics. Among various sensing materials, comparatively less attention has been paid to CeO₂ despite its good catalytic activity and high stability. In this review paper, we are focusing on CeO₂ gas sensors in pristine, doped, decorated, and composite forms. Using numerous examples, we have shown the great potential of CeO₂ for gas sensing. The main features of CeO₂ as a gas sensor include excellent environmental stability, the abundance of oxygen vacancies, high mechanical strength, cost-effectiveness, and good catalytic activity. However, low electrical conductivity is the main shortage of CeO₂ as a gas sensor. With a high emphasis on the sensing mechanism, we believe that this review paper is highly useful for researchers working in this field.