Synthesis of NiGa2O4 ultra-thin nanosheets for improved xylene sensing properties and selectivity

Abstract

Ultra-thin two-dimensional nanomaterials are ideal candidates for fabricating gas sensors due to their large specific surface area, high carrier mobility and atomic-level thickness; however, the development of ultra-thin two-dimensional nanomaterials still remains a challenge. In this work, NiGa₂O₄ nanosheets with a thickness of about 3 nm are successfully prepared by calcining the NiGa LDH template. Moreover, the gas sensor fabricated using NiGa₂O₄ nanosheets shows a high response to xylene (R_g/R_a ≈ 7.7, 10 ppm), remarkable selectivity, a low detection limit (0.3 ppm) and excellent stability at low optimum working temperature (190 °C). This work has promoted the development of high-performance gas sensors based on two-dimensional and wide band gap metal oxide semiconductor materials.