Universiti Teknologi Malaysia Institutional Repository

Influence of ZnO doping on structural, optical and pH-stimulus characteristics of silica-titania nanocomposite matrix

Islam, S. and Bakhtiar, H. and Bidin, N. and Salim, A. A. and Riaz, S. and Abbas, K. N. and Suan, L. P. and Naseem, S. (2018) Influence of ZnO doping on structural, optical and pH-stimulus characteristics of silica-titania nanocomposite matrix. Journal of Saudi Chemical Society, 22 (7). pp. 826-837. ISSN 1319-6103

[img]
Preview
PDF
2MB

Official URL: http://dx.doi.org/10.1016/j.jscs.2018.01.005

Abstract

In-situ sol-gel procedure is used to synthesize the silica-titania nanocomposite (SiO2-TiO2) as host matrix which is doped with ZnO and heated at 300 °C for 1 h for homogeneous and stable matrix surface. The mixture of organic dyes i.e. cresol red, bromophenol blue, phenol red and phenolphthalein is encapsulated within ZnO:SiO2-TiO2 nanocomposite for the evaluation of sensing activity at dynamic pH range 1–12. Microscopic findings showed that the synthesized nanocomposites have homogeneous crack-free porous coating with low roughness value of 9.7–7.6 nm. XRD analysis shows the formation of new phase ZnSiO3 after ZnO doping and heat treatment along with anatase phase of titania and silica. TEM analysis confirmed the spherical nanoparticles. The heterogeneous bonding of synthesized Zn:SiO2-TiO2 composites is investigated by FTIR. Surface analysis confirmed that prepared nanocomposites have high surface area, large pore diameters and mesoporous nature, which is desirable for good sensing behavior. Optical studies show that low refractive index (1.33–1.39) transparent nanocomposites (92–62% transparency in the visible range) are promising for sensing applications. TGA analysis shows that SiO2-TiO2 nanocomposites after ZnO doping and heat treatment are thermally stable. The fast response 0.15 s of the ZnO:SiO2-TiO2 nanocomposite coated fiber optic sensor is optimized at pH 12. The observed sensitivity is of 15 counts/pH with repeatability of 93% at 440 nm.

Item Type:Article
Uncontrolled Keywords:Fiber optic sensing, Silica-titania nanocomposite, Structural and optical properties, ZnO doping
Subjects:Q Science > QC Physics
Divisions:Science
ID Code:79666
Deposited By: Fazli Masari
Deposited On:28 Jan 2019 12:58
Last Modified:28 Jan 2019 12:58

Repository Staff Only: item control page