Nitrogen-doped In2O3 nanocrystals constituting hierarchical structures with enhanced gas-sensing properties

Doping indium oxide with nitrogen species is a strategy to extend its photoresponse to the visible region and to modify its band structure, enabling the material to have potential applications in photocatalysis, optoelectronics, and sensors. In this paper, we report on a simple solvothermal synthesis method for producing nitrogen-doped indium oxide nanocrystals that are composed of hierarchical structures. The samples were characterized with XRD, Raman spectroscopy, SEM, HRTEM, FTIR, XPS, UV-vis, and photoluminescence techniques, and further tested in the role of an ethanol gas sensing material. The optical properties and the gas-sensing performance of indium oxide can be tuned by controlling the nitrogen doping. Also, the nitrogen species, resulting from the nitrogen doping, function like a surface modifier to enhance the sensitivity of the sensors that were made from the nitrogen-doped indium oxides on their exposure to ethanol gas.