Abstract
Mesoporous materials have been extensively studied for various applications due to their high specific surface areas and well-interconnected uniform nanopores. Great attention has been paid to synthesizing stable functional mesoporous metal oxides for catalysis, energy storage and conversion, chemical sensing, and so forth. Heteroatom doping and surface modification of metal oxides are typical routes to improve their performance. However, it still remains challenging to directly and conveniently synthesize mesoporous metal oxides with both a specific functionalized surface and heteroatom-doped framework. Here, we report a one-step multicomponent coassembly to synthesize Pt nanoparticle-decorated Si-doped WO(3) nanowires interwoven into 3D mesoporous superstructures (Pt/Si-WO(3) NWIMSs) by using amphiphilic poly(ethylene oxide)-block-polystyrene (PEO-b-PS), Keggin polyoxometalates (H(4)SiW(12)O(40)) and hydrophobic (1,5-cyclooctadiene)dimethylplatinum(II) as the as structure-directing agent, tungsten precursor and platinum source, respectively. The Pt/Si-WO(3) NWIMSs exhibit a unique mesoporous structure consisting of 3D interwoven Si-doped WO(3) nanowires with surfaces homogeneously decorated by Pt nanoparticles. Because of the highly porous structure, excellent transport of carriers in nanowires, and rich WO(3)/Pt active interfaces, the semiconductor gas sensors based on Pt/Si-WO(3) NWIMSs show excellent sensing properties toward ethanol at low temperature (100 °C) with high sensitivity (S = 93 vs 50 ppm), low detection limit (0.5 ppm), fast response-recovery speed (17-7 s), excellent selectivity, and long-term stability.