Electronic and morphological dual modulation of NiO by indium-doping for highly improved xylene sensing

The development of oxide semiconductor-based gas sensing materials that can sensitively detect benzene compounds (e.g., xylene) is highly desirable but challenging due to their inherently low chemical reactivity. Herein, we report 2D ultrathin bimetallic nickel-indium oxide nanosheets as such high-performance xylene sensing materials. The introduction of In during the synthesis induces the formation of an ultrathin In-doped NiO nanosheet morphology with a 2-5 nm thickness and high surface area (141.8 m(2) g(-1)) through a topotactic transformation of NiIn-layered double hydroxide (LDH) precursors. Simultaneously, the substitution of high-valence In3+ in NiO leads to an electronic compensation effect, bringing a decreased hole concentration and increased chemisorbed oxygen species. The joint optimization of the morphology and electronic properties of NiO by In-doping provides more active centres for surface adsorption and the xylene sensing reaction. As a result, the In-doped NiO nanosheets exhibit much greater xylene response (R-gas/R-air = 9) than pristine NiO (R-gas/R-air < 2) to 10 ppm xylene at a low operating temperature of 160 degrees C.

Automated summary

The development of 2D ultrathin bimetallic nickel-indium oxide nanosheets as xylene sensing materials has shown significant improvement in sensitivity, outperforming pristine NiO while operating at a low temperature of 160 degrees C.