LAUSR

Semiconducting metal oxides have attracted increasing attention in various fields due to their intrinsic properties. In this study, a facile solvent evaporation induced multicomponent co-assembly (EIMCA) approach coupled with a car-bon-supported crystallization strategy, is employed to controllably synthesize crystalline mesoporous nickel oxide doped tungsten oxides in an acidic THF/H2O solution with poly(ethylene oxide)-b-polystyrene diblock copolymers (PEO-b-PS) as the structure-directing agent, tungsten (VI) chlorides as WO3 precursors and Ni(AcAc)2 as NiO precur-sor. The obtained materials possess a face-centered cubic (fcc) mesoporous structure, large pore size (~30 nm), high surface area (30-50 m2 g-1), large pore volume (0.15-0.19 cm3 g-1), and ultra large pore windows (12-16 nm) connecting adjacent mesopores, and the mesoporous WO3 framework was decorated by ultrafine NiO nanocrystals. Due to their well-connected porous structure and high surfaces with rich WO3-NiO interfaces, the composite materials exhibit su-perior gas sensing performance with ultrafast response (~4 s), high sensitivity (Ra/Rg = 58±5.1) and selectivity to 50 ppm H2S at relatively low working temperature (250 oC). The chemical mechanism study reveals complicated surface reac-tions WO3/NiO-based gas sensors and SO2, WS2 and NiS intermediates were found to be generated during gas sensing process.