Ordered Arrays of Bead-Chain-like In₂O₃ Nanorods and Their Enhanced Sensing Performance for Formaldehyde

Abstract

Here we present a class of formaldehyde (HCHO) gas sensors with strong responses based on ordered mesostructured In 2 O 3 nanorod arrays, which are synthesized via the nanocasting route by directly using the solvent-extracted mesoporous silica as a hard template. By choosing mesoporous silica with different pore sizes and interconnectivity as templates and varying the loading of indium resource on the silica template, we have obtained a series of mesostructured In 2 O 3 nanorod arrays with different textural parameters such as specific surface area, pore size, nanorod diameter, etc. The gas sensing properties for formaldehyde (HCHO) of the In 2 O 3 specimens were examined. The results reveal those mesostructured In 2 O 3 nanorod arrays possess much stronger responses to HCHO even at low concentrations than the bulk In 2 O 3 , and larger specific surface areas and pore sizes as well as smaller nanorod diameters would be beneficial for enhancing the sensing properties of In 2 O 3 .

Construction of Three-Dimensional Homogeneous NiCo2O4Core/Shell Nanostructure as High-Performance Electrodes for Supercapacitors

“…37,38 Third, the porous core/shell nanowire arrays directly grow on the conductive substrate, which can avoid the appearance of "dead volume" in electrode materials caused by existence of polymer binder and conductive additives.…”

“…36 Second, the formation of rich and welldefined micro/nano-structures provides many ion transport pathways for quick electrolyte ion diffusion and electron transfer. 37,38 Third, the porous core/shell nanowire arrays directly grow on the conductive substrate, which can avoid the appearance of "dead volume" in electrode materials caused by existence of polymer binder and conductive additives. 3,42 Therefore, it is highly desirable to develop a kind of three-dimensional homogeneous NiCo 2 O 4 core/shell materials on the conductive substrate.…”

Synthesis and High-Pressure Study of Corundum-Type In2O3

“…[3][4][5] The widespread use of In 2 O 3 in industrial processes covers the fabrication of window layers in solar cells, [6][7][8] light-emitting diodes, 9,10 electrochromic windows, 11 liquid-crystal displays, 12,13 and gas sensors. 14,15 Due to the scarcity and high cost to obtain indium metal, new 3 systems, like Sn-doped In 2 O 3 (ITO) and corundum-type In 2-2x Zn x Sn x O 3 (x ≤ 0.4, or ZITO), have been developed to cut the prize of the production system. [16][17][18] At ambient conditions In 2 O 3 usually crystallizes in the cubic bixbyite-type phase (space group (SG) Ia-3, N. 206, Z=16), 19 and other phases of In 2 O 3 can be obtained by the application of pressure and temperature: rhombohedral corundum-type (SG R-3c, N. 167, Z=6), orthorhombic Rh 2 O 3 -II type (SG Pbcn, N. 60, Z= 4), and orthorhombic α-Gd 2 S 3 -type (SG Pnma, N. 62, Z= 4).…”

Nanocube In2O3@RGO heterostructure based gas sensor for acetone and formaldehyde detection

“…34 Lai et al have demonstrated the improved formaldehyde gas sensing performance based on ordered arrays of bead-chain-like In 2 O 3 nanorods. 35 Yang et al synthesized the additive free In 2 O 3 cubes embedded with graphene and studied improved NO 2 sensing performance at room temperature. 36 Huang et al have synthesized ZnO QDs/ graphene nanocomposites and studied the room temperature formaldehyde sensing properties with improved performance and fast response and recovery times.…”