Enhanced room temperature ammonia gas sensing performance of ZnO-Cr2O3 heterostructured nanocomposites
ZnO-Cr2O3 nanocomposites (NCs) were prepared by simple two-step process. Prepared samples were subjected to structural characterization via X-ray diffraction (XRD) technique and confirmed the phase and purity of composites. Gas sensing performance of ZnO-Cr2O3 nanocomposites was studied at room temperature and it is observed that ZnO-Cr2O3 nanocomposite based gas sensor has shown tremendous increase in response towards ammonia when compared to pure ZnO based gas sensors. Response and recovery transients of the ZnO-Cr2O3 gas sensor towards various concentrations of ammonia were recorded at room temperature. The response and recovery times of the sensor were also calculated as ∼30 s and 48 s respectively. Long term stability of the sensor was studied and discussed. The enhanced sensing performance of the ZnO-Cr2O3 nanocomposites based gas sensor is attributed to the p-n heterojunction formed between n-ZnO and p-Cr2O3.