Room temperature photoelectric NO2 gas sensor based on direct growth of walnut-like In2O3 nanostructures

Abstract Direct growth of walnut-like In 2 O 3 nanostructures on the interdigited electrode substrate have been acquired via a facile hydrothermal approach, followed by an appropriate thermal treatment. The morphologies of the synthesized In 2 O 3 are investigated and the growth mechanism of the In 2 O 3 film is proposed. Observation of the individual walnut-like In 2 O 3 indicates the elegant architecture is composed of few dents and prisms. The synthesized walnut-like In 2 O 3 nanostructures is exploited to fabricate a photoelectric gas sensor that exhibits an ultrahigh sensitivity (219) to 50 ppm NO 2 with irradiation of UV light (λ = 365 nm) of 1.2 mW/cm 2 . The stability and selectivity of walnut-like In 2 O 3 nanostructures were carried out. The photoelectronic gas sensing mechanisms of In 2 O 3 were proposed in detail to understand the effect of UV irradiation in the NO 2 detection process.