One pot synthesis of mesoporous ZnO–SiO 2 nanocomposite as high performance humidity sensor

Humidity‐Sensing Properties of Ag0 Nanoparticles Supported on WO3‐SiO2 with Super Rapid Response and Excellent Stability

“…All the samples exhibit similar patterns, with a main peak at 2θ = 0.8°, which is related to the mesoporosity of the samples. [13] Two additional peaks in the region 2θ = 1.5-2.0°corresponds to the long-range ordering or cylindrical mesopores. The hybrid nanocomposites show well-resolved diffraction peaks that can be indexed to the (100), (110), and (200) reflections of 2D hexagonal mesostructure of space group p6mm.…”

“…[13] All the samples show a steep inflection in P/P 0 Ͼ 0.6, corresponding to the capillary condensation, which is the result of a sudden jump in the adsorption volume and denotes the mesoporous structure and narrow pore-size distributions of all the samples. The shape of Ag-WO 3 /SiO 2 nanocomposites was well maintained even after the impregnation with Ag nanoparticles, suggesting the mesoporous nature of the complex nanohybrids.…”

“…The nanocomposite Ag-WO 3 /SiO 2 (3) displays a well-ordered 2-D p6mm regular hexagonal mesoporous structure with uniform channels that are the characteristic (001) direction of the one-dimensional channels templated by the block copolymer P123. [13] The mesoporous channels and long-range order of the mesopores remain intact even after loading of the Ag nanoparticles. The EDX spectra of WO 3 /SiO 2 and Ag-WO 3 /SiO 2 (3) are shown in Figure S2(a) and (b), respectively.…”

“…[9][10][11][12] Mesoporous SiO 2 , owing to its high specific surface area, large pore volume, high thermal stability, and long, ordered pore channels, can stimulate chemical reactivity and physical adsorption of water molecules and so has attracted significant interest in designing efficient RH sensors. [13][14][15] Yuan et al modified the SiO 2 framework by using ZnO nanoparticles through a simple, one-step sol-gel route. The obtained nanocomposite sensor showed a change in impedance of four orders of magnitude, 2 % hysteresis error, and response and recovery times of 50 and 100 s, respectively, in 11-95 % RH.…”

Comparison of the synthesis routes for the ZnO/porous silica nanocomposite

“…While incorporation of NPs into molecular sieves can solve the stability and agglomeration problems, the insertion process is a challenge by itself. Various fabrication techniques to produce NPs inside the molecular sieves have been proposed, namely: wet impregnation, sol-gel method, radio-frequency sputtering, one-pot surfactant-assisted procedure, direct incorporation, grafting with organometallic compounds and others [7][8][9][10][11][12][13][14][15].…”