Nanoscale\nPtO₂ Catalysts-Loaded SnO₂ Multichannel Nanofibers\ntoward Highly Sensitive Acetone\nSensor

Abstract

PtO₂ nanocatalysts-loaded\nSnO₂ multichannel nanofibers (PtO₂-SnO₂ MCNFs) were synthesized by single-spinneret electrospinning combined\nwith apoferritin and two immiscible polymers, i.e., poly­(vinylpyrrolidone)\nand polyacrylonitrile. The apoferritin, which can encapsulate nanoparticles\nwithin a small inner cavity (8 nm), was used as a catalyst loading\ntemplate for an effective functionalization of the PtO₂ catalysts. Taking advantage of the multichannel structure with a\nhigh porosity, effective activation of catalysts on both interior\nand exterior site of MCNFs was realized. As a result, under high humidity\ncondition (95% RH), PtO₂-SnO₂ MCNFs exhibited\na remarkably high acetone response (<i>R</i>_air/<i>R</i>_gas = 194.15) toward 5 ppm acetone\ngases, superior selectivity to acetone molecules among various interfering\ngas species, and excellent stability during 30 cycles of response\nand recovery toward 1 ppm acetone gases. In this work, we first demonstrate\nthe high suitability of multichannel semiconducting metal oxides structure\nfunctionalized by apoferritin-encapsulated catalytic nanoparticles\nas highly sensitive and selective gas-sensing layer.