Pt Nanoparticles Sensitized Ordered Mesoporous WO<inf>3</inf> Semiconductor: Gas Sensing Performance and Mechanism Study

Abstract

In this study, a straightforward coassembly strategy is demonstrated to synthesize Pt sensitized mesoporous WO3 with crystalline framework through the simultaneous coassembly of amphiphilic poly(ethylene oxide)-b-polystyrene, hydrophobic platinum precursors, and hydrophilic tungsten precursors. The obtained WO3/Pt nanocomposites possess large pore size (≈13 nm), high surface area (128 m2 g−1), large pore volume (0.32 cm3 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 WO3/Pt nanocomposites, the partially oxidized Pt nanoparticles that chemically and electronically sensitize the crystalline WO3 matrix, dramatically enhance the sensitivity and selectivity.