Highly dispersed TiO₂nanocrystals and carbon dots on reduced graphene oxide: Ternary nanocomposites for acceleratedphotocatalytic water disinfection

TY - JOUR

T1 - Highly dispersed TiO2nanocrystals and carbon dots on reduced graphene oxide

T2 - Ternary nanocomposites for acceleratedphotocatalytic water disinfection

AU - Zeng, Xiangkang

AU - Wang, Zhouyou

AU - Meng, Na

AU - McCarthy, David T.

AU - Deletic, Ana

AU - Pan, Jia-Hong

AU - Zhang, Xiwang

PY - 2017/3

Y1 - 2017/3

N2 - Graphene is widely used as a catalyst support for improved charge separation in TiO2 photocatalysis. However, the surface oxygen reduction activity of TiO2 /graphene might be hindered due to the electron storage ability of graphene. In this study, highly dispersed TiO2 and carbon dots (C-dots) co-decorated reduced graphene oxide (CTR) is synthesized via a simple hydrothermal reaction using TiCl4 and glucose. Transmission electron microscope, X-ray diffraction, Raman spectroscopy, thermogravimetric analysis and Fourier transform IR spectroscopy are employed to characterize the CTR nanocomposite. The com- parison experiment confirmed that C-dots were sourced from the carbonization of glucose. Glucose and TiCl4 which are mutual dispersants, are critical for forming highly dispersed and uniform-sized C-dots and TiO2 nanocrystals. With well dispersed TiO2 and C-dots at separated sites of reduced graphene oxide surface, CTR shows enhanced photocatalytic bacterial inactivation performance under simulated solar light. As confirmed by the reactive oxygen species production, the generation of superoxide anion (O2•−) and hydrogen peroxide (H2O2 ) is improved. The electrochemical characterization reveals that charge separation in CTR photocatalysis is also promoted. Taken together, the concurrently improved charge separation and surface oxygen reduction activity contribute to an accelerated photocatalytic bacteria inactivation process.

AB - Graphene is widely used as a catalyst support for improved charge separation in TiO2 photocatalysis. However, the surface oxygen reduction activity of TiO2 /graphene might be hindered due to the electron storage ability of graphene. In this study, highly dispersed TiO2 and carbon dots (C-dots) co-decorated reduced graphene oxide (CTR) is synthesized via a simple hydrothermal reaction using TiCl4 and glucose. Transmission electron microscope, X-ray diffraction, Raman spectroscopy, thermogravimetric analysis and Fourier transform IR spectroscopy are employed to characterize the CTR nanocomposite. The com- parison experiment confirmed that C-dots were sourced from the carbonization of glucose. Glucose and TiCl4 which are mutual dispersants, are critical for forming highly dispersed and uniform-sized C-dots and TiO2 nanocrystals. With well dispersed TiO2 and C-dots at separated sites of reduced graphene oxide surface, CTR shows enhanced photocatalytic bacterial inactivation performance under simulated solar light. As confirmed by the reactive oxygen species production, the generation of superoxide anion (O2•−) and hydrogen peroxide (H2O2 ) is improved. The electrochemical characterization reveals that charge separation in CTR photocatalysis is also promoted. Taken together, the concurrently improved charge separation and surface oxygen reduction activity contribute to an accelerated photocatalytic bacteria inactivation process.

KW - TiO2

KW - Carbon dots

KW - Reduced graphene oxide

KW - Photocatalysis

KW - Disinfection

U2 - 10.1016/j.apcatb.2016.09.014

DO - 10.1016/j.apcatb.2016.09.014

M3 - Article

VL - 202

SP - 33

EP - 41

JO - Applied Catalysis B-Environmental

JF - Applied Catalysis B-Environmental

SN - 0926-3373

ER -