Enhanced catalytic activity of the surface modified TiO₂-MWCNT nanocomposites under visible light

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• 作者：Mojca Božič^a ; ^{mojca.bozic@um.si" class="auth_mail" title="E-mail the corresponding author} ; Vera Vivod^a ; Robert Vogrinčič^a ; Irena Ban^b ; Gregor Jak&scaron ; a^c ; Silvo Hribernik^a ; Darinka Fakin^a ; Vanja Kokol^a
• 关键词：TiO2 ; Carbon nanotube ; Laccase ; Surface functionalization ; Extended light photocatalysis
• 刊名：Journal of Colloid and Interface Science
• 出版年：2016
• 出版时间：1 March 2016
• 年：2016
• 卷：465
• 期：Complete
• 页码：93-105
• 全文大小：2286 K

文摘

Fusing multiwall carbon nanotubes (MWCNTs) with TiO₂ at the nano-scale level promotes the separation of those electron–hole charges generated upon UV and daylight irradiation. In this study, we investigated facile sonochemical synthesis, combined with the calcination process for the preparations of TiO₂-MWCNT composites with different mole ratios of titanium and carbon. In order to produce stable nano dispersions we exploited an innovative biotechnology-based approach for the covalent functionalizations of TiO₂-MWCNTs with in-situ synthesized soluble phenoxazine dye molecules. The none and functionalized TiO₂-MWCNTs composites were analyzed by a range of analytical techniques including XRD, Raman, XPS, SEM and UV–vis diffuse reflectance spectroscopy (DRS), and dynamic light scattering (DLS). The photocatalytic activity was evaluated toward the liquid-phase degradation of MB in aqueous solution under both UV and visible light irradiation. TiO₂-MWCNTs with optimized mole ratio exhibit much higher photocatalytic activity and stability than bare TiO₂. The as-prepared TiO₂-MWCNTs photocatalyst possessed good adsorptivity of dyes, extended light absorption range and efficient charge separation properties simultaneously. The results indicated that the soluble phenoxazine dyes and amino-benzenesulfonic acid monomers were covalently grafted on to the surfaces of TiO₂-MCNTs, which promoted good aquatic dispersibility and extended light absorption, resulting in increased photocatalytic efficiency.