Porous Hierarchical In₂O₃ Micro-/Nanostructures: Preparation, Formation Mechanism, and Their Application in Gas Sensors for Noxious Volatile Organic Compound Detection

Abstract

A porous hierarchical In2O3 micro-/nanostructure was prepared by oxidizing In2S3 precursors for gas sensor applications. The formation mechanism of the porous structure was investigated systemically by means of simultaneous thermogravimetry and differential thermal analysis, conventional X-ray diffraction, and energy-dispersive XRD cooperated with field-emission scanning electronic microscopy observations. In gas-sensing measurements with noxious volatile organic compounds as target gases, the gas sensor based on porous hierarchical In2O3 micro-/nanostructures showed a sensitive performance with a large detecting concentration range. Besides, the as-fabricated gas sensor also exhibited significant selectivity toward each target gas. Both the sensitivity and the selectivity of the porous hierarchical In2O3 micro-/nanostructure-based gas sensor enable it to be potentially applied for environmental monitoring toward noxious volatile organic compounds. Furthermore, the gas-sensing mechanism was also demonstrated from the kinetic process of gas adsorption−desorption.

Structural characterization of In2O3 hierarchical microwires synthesized through decomposition thermal treatment of InSe single crystal

“…Recent works have reported the synthesis of rod-like microbundles [18] and of hierarchical, hollow and flower-like microsphere [11,19,20] by solvothermal route, based on additives mediated self-assembly and followed by an annealing process. Liu et al [21] and Zhang et al [22] have obtained porous hierarchical In 2 O 3 micro-/nanostructures by annealing in a muffle furnace In 2 S 3 micro/nano-structures which were previously hydrothermally synthesized. The development of facile, economical and effective methods for creating controllable architectures has induced Yin et al [23] to synthesize a variety of different In 2 O 3 submicron/nanostructures including arrow-like, bead-like, bouquet, comb-like wires and regular polyhedra using a catalyst-free chemical vapor deposition (CVD) route, in different regions of silicon substrate by heating a pure In grain source.…”

Developing novel gas sensors for NO2 detection based on Ce(1-x)MXO2, {M = Ru, In} solid solutions

“…In this context, lanthanum [7], indium [10][11][12][13][14] and ruthenium [15,16], are elements that have been successfully tested as oxides for some applications like gas-sensor materials and in the present work, are added to ceria.…”

Enhanced NO2 sensing characteristics of Pd-functionalized networked In2O3 nanowires

“…Accordingly, it has a wide range of practical applications, including optoelectronic devices [6], solar cells [7], field effect transistors [8], electric-double-layer transistors [9], Fabry-Perot resonators [10], thin-film transistors [11], bio sensors, and gas sensors. In 2 O 3 has attracted much attention for its ability to sense both oxidizing and reducing gases, including O 2 [12], O 3 [13,14], nitric oxides [15], CO [16,17], H 2 S [18], H 2 [16,17], and noxious volatile organic compounds [19].…”