Template-derived net-like SnO2 nanoarrays for robust H2S sensing with broad-range linear response

Abstract

Porous film of semiconducting metal oxides provides large surface area for efficient gas-sold interactions. Nanocasting using solid templates such as closely packed colloidal crystals represents a straightforward strategy for creating ordered porous materials, yet the preparation of templates typically involves a complex, time-consuming process of self-assembly. In this study, on-chip preparation of SnO2 nanoarrays with porous net-like structure has been achieved by employing in-situ grown NiO nanoarrays as the template. In contrast to the poor stability of the response of NiO nanoarrays to H2S, the as-prepared SnO2 nanoarrays exhibit excellent selectivity, stability and capability of responding linearly to H2S in a broad concentration range (0.4–80 ppm). Due to the free access of gas molecules to the porous net-like microstructure, SnO2 nanoarrays are found to possess much higher and faster H2S response as compared to the dense film counterpart. A portable sensor device based on SnO2 nanoarrays has also been fabricated, which demonstrates the practical H2S detection with high accuracy.