Microwave-Solvothermal Synthesis of Mesoporous CeO₂/CNCs Nanocomposite for Enhanced Room Temperature NO₂ Detection

Nitrogen dioxide (NO₂) gas sensors are pivotal in upholding environmental integrity and human health, necessitating heightened sensitivity and exceptional selectivity. Despite the prevalent use of metal oxide semiconductors (MOSs) for NO₂ detection, extant solutions exhibit shortcomings in meeting practical application criteria, specifically in response, selectivity, and operational temperatures. Here, we successfully employed a facile microwave-solvothermal method to synthesize a mesoporous CeO₂/CNCs nanocomposite. This methodology entails the rapid and comprehensive dispersion of CeO₂ nanoparticles onto helical carbon nanocoils (CNCs), resulting in augmented electronic conductivity and an abundance of active sites within the composite. Consequently, the gas-sensing sensitivity of the nanocomposite at room temperature experienced a notable enhancement. Moreover, the presence of cerium oxide and the conversion of Ce³⁺ and Ce⁴⁺ ions facilitated the generation of oxygen vacancies in the composites, thereby further amplifying the sensing performance. Experimental outcomes demonstrate that the nanocomposite exhibited an approximate 9-fold increase in response to 50 ppm NO₂ in comparison to pure CNCs at room temperature. Additionally, the CeO₂/CNCs sensor displayed remarkable selectivity towards NO₂ when exposed to gases such as NH₃, CO, SO₂, CO₂, and C₂H₅OH. This straightforward microwave-solvothermal method presents an appealing strategy for the research and development of intelligent sensors based on CNCs nanomaterials.