▎ 摘　　要

Facile synthesis of the W18O49/Graphene (W18O49/G) nanocomposites were developed by a graphene assisted hydrothermal route, in which p-n heterojunction was successfully constructed for highly sensitive ethanol gas sensors. Their structure, morphology, and chemical compositions were examined by XRD, SEM, HRTEM, XPS, N-2 adsorption-desorption techniques. The well-defined W18O49/G nanocomposites consisted of interlaced nanowires offered unique p-n junctions at the heterointerfaces, which could increase the point defects and vacancies in the vicinity of heterostructures, promoting gas adsorption and gas-sensing reactions. Gas-sensing tests confirmed that the combination of W18O49 nanowires and graphene endowed crucial advantages for ethanol detection, such as high response and selectivity, rapid responding and recovering, and excellent ability. In comparison with previous published works, the W18O49/G sensor also displayed outstanding ethanol sensing performance. A possible gas-sensing mechanism based on this novel W18O49/G nanocomposites was discussed.