A study on carbon nanotube titanium dioxide hybrids: experiment and calculation

Minh Thuy Nguyen, Cao Khang Nguyen, Thi Mai Phuong Vu, Quoc Van Duong, Tien Lam Pham and Tien Cuong Nguyen

Abstract

Carbon nanotubes (CNTs) were coated TiO₂ nanoparticles via sol–gel process using titanium tetra-isoproxide Ti[OCH(CH₃)₂]₄ (TTIP). The structure of TiO₂/CNT hybrid samples was determined by x-ray diffractometer D5005 (Siemen) with CuKα radiation. Their morphology and sizes were investigated with FE-SEM and HR-TEM, which shows that nanoparticles were coated on CNTs. The UV–vis absorption results indicate interaction between TiO₂ and CNTs, the composite material can absorb at higher wavelength and the absorption even covers the whole range of visible region. By investigating different addition ratios of CNT on the photocatalytic activity of TiO₂/CNTs, we find that the higher ratio in TiO₂/CNT will decrease the photocatalytic activity. We have calculated the electronic structure of the anatase TiO₂ and single-wall carbon nanotube (SWCNT) by first-principles stimulation. We investigate the property in hybrid structure: molecular and small clusters of TiO₂ adsorbed on SWCNT support using density functional calculation. The energy and charge distribution calculations show that SWCNT can make TiO₂ clusters become more stable in the hybrid system