LAUSR

Abstract Herein, a WO3-CuWO4 nanostructured heterojunction was prepared by a facile two-step hydrothermal method. It is composed of a WO3 square microplate and CuWO4 nanoparticles. Then, the gas sensing properties were investigated under optimal operating temperature (120 °C). The WO3-CuWO4 heterostructure shows good sensing performance towards n-butanol, with a response value up to 9.4 to towards 30 ppm n-butanol, and the response value is about 3 times higher than that of pristine WO3. Its detection limit for n-butanol is 0.1 ppm, which indicates a potential application in lower concentration detection. Moreover, the response time of WO3-CuWO4 nanostructured heterojunction and the pristine WO3 are 21 s and 240 s respectively, revealing that there is a faster gas sensing process in the heterostructure. A possible sensing mechanism was then proposed on the basis of experimental data and band structure analysis. The significant enhancement of WO3-CuWO4 heterostructure could be attributed to the formation of heterojunction, which brings electronic sensitization and electron transport pathway modulation. The work offered a kind of novel and cost-effective sensing materials, and inspired more novel devices based on nanostructured heterojunction mechanism.