Hydrothermal Synthesizing Di-crystalline TiO₂ and CNT-COCl/TiO₂ Nanocomposites to Degrade Bisphenol A Irradiated with Visible Light - Effect of pH and PO₄^3-

Title:Hydrothermal Synthesizing Di-crystalline TiO₂ and CNT-COCl/TiO₂ Nanocomposites to Degrade Bisphenol A Irradiated with Visible Light - Effect of pH and PO₄^3-

Volume: 12 Issue: 2

Author(s): Ching Yuan, Chung-Hsuang Hung and Bo-Chao Chuang

Affiliation:

Keywords: Acyl chloride-grafted carbon nanotube, bisphenol A, di-crystalline, hydrothermal, photocatalysis, titanium dioxide.

Abstract: Background: Bisphenol A (BPA) is widely used in its monomeric form in the manufacture of poly carbonate plastics, epoxy resins, and flame retardant. The visible photodegradation of BPA with di-crystalline TiO₂ and CNT-COCl/TiO₂ nanocomposites was investigated in this study.

Methods: The di-crystalline phases of nanocomposites were observed via preparing 1 mL HNO3 of 0.4-1.0 M for synthesis. The CNT-COCl/TiO₂ nanocomposites were synthesized by doping acyl chloride- grafted CNTs onto titanium tetraisopropoxide followed by a hydrothermal method. The precursor ratio of CNT-COCl to Ti was set at 1/99 (w/w).

Results: Results showed distinguish increase in red-shift effect of characteristic wavelength at higher rutile crystalline phase. It addressed that a faster degradation rate of BPA was exhibited for di-crystalline nano-composites under visible irradiation compared to that for P25. Further, the BPA degradation rate was much higher in the photocatalytc system using di-crystalline TiO₂ doped with CN-COCl. Both solution pH and addition of phosphate showed significant influences on the photo-activity of CNT-COCl/TiO₂. The promotional effect caused by phosphate was ascribed to a proper charge separation and high amount of hydroxide radical formation. A degradation rate of 59.5 % was found for the synthesized CNTCOCl/ TiO₂ with 50% rutile crystalline phase at pH 9.0 and 10^-4 M PO₄^3-.

Conclusion: A novel CNT-COCl/TiO₂ photocatalyst was successfully synthesized and characterized. The titanium photocatalysts can be successfully excited by visible irradiation via adjusting the ratio of crystalline phase. Compare with peer carbon-doping TiO₂, the CNT-COCl/TiO₂ fabricated in this study has superior photocatalytic activity in visible light.

Cite this article as:

Yuan Ching, Hung Chung-Hsuang and Chuang Bo-Chao, Hydrothermal Synthesizing Di-crystalline TiO₂ and CNT-COCl/TiO₂ Nanocomposites to Degrade Bisphenol A Irradiated with Visible Light - Effect of pH and PO₄^3-, Current Nanoscience 2016; 12 (2) . https://dx.doi.org/10.2174/1573413711666151028192352