A highly selective room-temperature formaldehyde gas sensor based on vertically aligned 1D NiCo2O4 nanoneedles

Abstract

The challenge to detect formaldehyde gas at room-temperature (RT) using metal oxide semiconductors is still unaddressed. High temperature requirement of metal oxide gas sensors restricts their usage in various hand-held devices. To address this unattended regime of metal oxide gas sensors,a novel RT-based formaldehyde sensor using the 1D nickel cobalt oxide (NiCo2O4) has been reported. It is synthesized via a single-step hydrothermal route. FESEM and TEM micrographs reveal micro-flower like morphology, consisting of huge numbers of interwoven, vertically aligned 1D nanoneedles while chemical characterization data confirm successful growth of this binary metal oxide. This sensor exhibits quick response/recovery time (22 s /57 s) at RT over the linear region of 10–100 ppm formaldehyde with excellent selectivity and stability. Thus, it paves an avenue for development of affordable, RT gas sensing devices for air quality monitoring applications.