Position-Selective Growth of WO₃ Nanosheets for NH₃ Gas Sensors

In this study, chemical vapor deposition of WO3 via graphene-catalyzed thermal transport is utilized to prepare position-selective WO3 micro/nanostructures. The effects of growth temperature and oxygen concentration on the structure, morphology, surface chemical states, and electrical properties are studied. The growth temperature and oxygen concentration are found to alter the resulting morphology and electrical properties. The combined application of high temperature and high oxygen concentration results in porous WO3 nanosheets with active surfaces. The prepared nanosheets are utilized for room-temperature NH3 gas sensing, and they exhibit good sensitivity, response time, and recovery time.