Pt Nanoparticles Sensitized Ordered Mesoporous WO3 Semiconductor: Gas Sensing Performance and Mechanism Study

Abstract In this study, a straightforward coassembly strategy is demonstrated to synthesize Pt sensitized mesoporous WO 3 with crystalline framework through the simultaneous coassembly of amphiphilic poly(ethylene oxide)‐ b ‐polystyrene, hydrophobic platinum precursors, and hydrophilic tungsten precursors. The obtained WO 3 /Pt nanocomposites possess large pore size (≈13 nm), high surface area (128 m 2 g −1 ), large pore volume (0.32 cm 3 g −1 ), and Pt nanoparticles (≈4 nm) in situ homogeneously distributed in mesopores, and they exhibit excellent catalytic sensing response to CO of low concentration at low working temperature with good sensitivity, ultrashort response‐recovery time (16 s/1 s), and high selectivity. In‐depth study reveals that besides the contribution from the fast diffusion of gaseous molecules and rich interfaces in mesoporous WO 3 /Pt nanocomposites, the partially oxidized Pt nanoparticles that chemically and electronically sensitize the crystalline WO 3 matrix, dramatically enhance the sensitivity and selectivity.