Porous Ga–In Bimetallic Oxide Nanofibers with Controllable Structures for Ultrasensitive and Selective Detection of Formaldehyde

Abstract

The design of appropriate composite materials with unique surface structures is an important strategy to achieve ideal chemical gas sensing. In this paper, efficient and selective detection of formaldehyde vapor has been realized by a gas sensor based on porous GaInO nanofibers assembled by small building blocks. By tuning the Ga/In atomic ratios in the materials, crystallite phase, nanostructure, and band gap of as-obtained GaInO nanofibers can be rationally altered. This further offers a good opportunity to optimize the gas sensing performances. In particular, the sensor based on porous GaInO nanofibers assembled by small nanoparticles (∼4.6 nm) exhibits best sensing performances. Toward 100 ppm formaldehyde, its highest response (R/R = 52.4, at 150 °C) is ∼4 times higher than that of the pure InO (R/R = 13.0, at 200 °C). Meanwhile, it has superior ability to selectively detect formaldehyde against other interfering volatile organic compound gases. The significantly improved sensing performance makes the GaInO sensor very promising for selective detection of formaldehyde.

Facile synthesis of In2O3 nanoparticles with high response to formaldehyde at low temperature

“…It can be seen that all the samples have strong absorption at the wavelength of 300 nm, which is attributed to the electronic transition from the valence band to the conduction band . The band gap energies ( E g ) are calculated using the Taucs Equation 3:…”

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

“…[24][25][26] The sensing performances are regulated by both the nanostructures and electronic properties of the sensing materials. While the nanostructures determine the density of surface sensing centres and the ability to efficiently transfer gas molecules, [27][28][29][30] the electronic properties (e.g., carrier concentration, Fermi level) largely control the surface chemisorption and sensing capability. [31][32][33][34][35] Therefore, for an oxide semiconductor to be an ideal sensing material, it has to have optimized nanostructures as well as electronic properties that can facilitate the surface chemisorption of oxygen species while activating chemical sensing reactions with benzene compounds.…”

Microstructure and Optical Properties of Nanostructural Thin Films Fabricated through Oxidation of Au–Sn Intermetallic Compounds

“…Simultaneously, the extensive surfaces of oxides (especially heteroatom-doped oxides) are great platforms for catalytic reactions because most of them depend strongly on the structure of the surfaces and interfaces [ 1 , 16 , 17 ]. Therefore, materials with porous architectures [ 3 ] or hierarchical nanostructures [ 18 ] and with large specific surface areas can substantially increase their surface activity sites to create excellent catalytic materials for environmental and energy applications [ 17 , 19 ].…”