Carbon-Dot-Sensitized, Nitrogen-Doped TiO2in Mesoporous Silica for Water Decontamination through Nonhydrophobic Enrichment-Degradation Mode

Cheng, Chen, Tan, Xianjun, Lu, Deli, Wang, Lingzhi, Sen, Tapas orcid iconORCID: 0000-0002-0463-7485, Lei, Juying, El-Toni, Ahmed Mohamed, Zhang, Jinlong, Zhang, Fan et al (2015) Carbon-Dot-Sensitized, Nitrogen-Doped TiO2in Mesoporous Silica for Water Decontamination through Nonhydrophobic Enrichment-Degradation Mode. Chemistry - A European Journal, 21 (49). pp. 17944-17950. ISSN 1521-3765

[thumbnail of Author Accepted Manuscript]
Preview
PDF (Author Accepted Manuscript) - Accepted Version
Available under License Creative Commons Attribution Non-commercial No Derivatives.

574kB

Official URL: http://dx.doi.org/10.1002/chem.201502301

Abstract

Mesoporous silica synthesized from the co-condensation of tetraethoxysilane and silylated carbon dot containing amide group has been adopted as the carrier for the in-situ growth of TiO2 through an impregnation-hydrothermal crystallization process. Benefitted from the initial complexing between the titania precursor and carbon dot, highly dispersed anatase TiO2 nanoparticles can be formed inside the mesoporous channel. The hybrid material possesses ordered hexagonal mesostructure with a p6mm symmetry, high specific surface area (446.27 m2g-1), large pore volume (0.57 cm3g-1), uniform pore size (5.11 nm) and a wide absorption band between 300-550 nm. TiO2 nanocrystals are anchored to carbon dot through bonds of Ti-O-N and Ti-O-C as revealed by X-ray photoelectron spectroscopy. Moreover, the nitrogen doping of TiO2 is also verified by the formation of Ti-N bond. This composite shows excellent adsorption capability to organic 2, 4-dichlorophenol and acid orange 7 with electron-deficient aromatic ring through the electron donor-acceptor interaction between carbon dot and organics instead of hydrophobic effect as analyzed by the contact angle analysis, which can be photocatalytically recycled through visible light irradiation after the adsorption. The narrowed bandgap by nitrogen doping and the photosensitization effect of carbon dot are revealed to be co-responsible for the visible-light activity of TiO2. The adsorption capacity does not suffer obvious loss after being recycled 3 times.


Repository Staff Only: item control page