A nanostructured Cr2O3/WO3 p-n junction sensor for highly sensitive detection of butanone

The highly sensitive detection of butanone was achieved by the WO3 nanosheets-Cr2O3 nanoparticles (denoted as "Cr2O3/WO3") p-n junction nanocomposite which was synthesized via a facile two-step hydrothermal process. The structure, morphology and compositions of the as-synthesized Cr2O3/WO3 nanocomposite were characterized by XRD, SEM, TEM, HRTEM, XPS, and BET. In the gas sensing test, the response of the Cr2O3/WO3 nanocomposite (Cr/W = 1:40, 1:10) to 100 ppm butanone at 180 A degrees C can reach to 40.51 and 38.26, respectively, which was much higher than that of independent WO3 nanosheets (10.7). Moreover, the Cr2O3/WO3 nanocomposite sensor shows rapid response (ca. 9 s)/recovery (ca. 15 s) time to 5 ppm butanone. In this work, a possible gas sensing mechanism of Cr2O3/WO3 nanocomposite sensor was also discussed based on p-n junction. The superior gas sensor properties demonstrate that Cr2O3/WO3 nanocomposite is a potential material for monitoring butanone.