Nanoscale PtO 2 Catalysts-Loaded SnO 2 Multichannel Nanofibers toward Highly Sensitive Acetone Sensor.

PtO2 nanocatalysts-loaded SnO2 multichannel nanofibers (PtO2-SnO2 MCNFs) were synthesized by single-spinneret electrospinning combined with apoferritin and two immiscible polymers, i.e., polyvinylpyrrolidone and polyacrylonitrile. The apoferritin which can encapsulate nanoparticles within small inner cavity (8 nm) was used as a catalyst loading template for effective functionalization of PtO2 catalysts. Taking advantage of the multichannel structure with high porosity, effective activation of catalysts on both the interior and exterior site of MCNFs was realized. As a result, under high humidity condition (95% RH), PtO2-SnO2 MCNFs exhibited remarkably high acetone response (Rair/Rgas = 194.15) toward 5 ppm acetone gases, superior selectivity to acetone molecules among various interfering gas species, and excellent stability during 30 cycles of response and recovery toward 1 ppm acetone gases. In this work, we firstly demonstrate the high suitability of multichannel semiconducting metal oxides structure functionalized by apoferritin encapsulated catalytic nanoparticles as highly sensitive and selective gas sensing layer.