UiO-66 metal–organic framework-derived ZrO2/ZnO mesoporous materials for high-efficiency detection of NO2 at room temperature

Abstract

To overcome the drawbacks of low sensitivity and limited selectivity exhibited by metal oxide sensitive materials, a metal–organic framework (MOF) derived composite (marked as UZZ) was constructed via a combined wet chemical method. UiO-66 was used as the precursor with the introduction of ZnO. The ZrO₂ component in UZZ retains the unique octahedral configuration of UiO-66; on its folded surface, a large number of ZnO particles grow, whose sizes range from 20 to 40 nm. The composite exhibits excellent gas sensitivity to NO₂ at room temperature. Exemplarily, the gas sensitive response to 100 ppm NO₂ is 40.35, with a response time of 1.4 s and a detection limit as low as the 50 ppb level, and the stability is up to 8 weeks. The presence of numerous oxygen vacancies and n–n type heterojunctions on the surface of the UZZ composite synergistically enhances the gas-sensing performance. This finding provides a significant reference for developing new efficient and high-sensitivity metal oxide sensitive materials based on MOFs.