Ultrasensitive and highly selective detection of acetone based on Au@WO3-SnO2 corrugated nanofibers

Abstract

The design of one-dimensional semiconductor metal oxides (SMOs) with porous structure has attracted tremendous attention owing to their larger specific surface area and a greater number of surface-active sites. Herein, Au@WO3-SnO2 nanofibers were fabricated through post-synthetic hydrothermal treatment which employed self-assembly A-stage phenolic resin as a sacrificial template. The nanopores observed in the Au@WO3-SnO2 nanofibers had diameters of about 3.5 nm. The nanoporous WO3-SnO2 nanofibers with well-dispersed tungsten species, exhibit excellent sensing performance, even at parts per billion level concentrations of gases. In a comparison with Au@SnO2 sample, the Au@WO3-SnO2 nanofibers exhibited a five times higher response (S = 79.6) to 0.5 ppm acetone at 150 °C and a good acetone selectivity. Furthermore, the Au@WO3-SnO2 nanofibers-based sensor also possessed good long-term stability. The extraordinary sensing performance can be attributed to the porous structure, highly one-dimensional interconnection, larger specific surface area, and WO3/SnO2 heterostructure. The approach proposed for functionalized WO3-SnO2 nanofibers in this work may contribute to the potential application in human health breath analysis by non-invasive detection.