Preparation of Carbon‐Nanotube‐supported TiO₂ for Enhanced Dye‐degrading Photocatalytic Activity

Abstract

Titanium dioxide-carbon nanotube (TiO 2 -CNT) nanocomposites were successfully synthesized by a sol-gel method. The prepared TiO 2 -CNT samples were characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). The photocatalytic activity of the samples was tested by photodegradation of methylene blue (MB) and methyl orange (MO) in aqueous solution under UV-light irradiation. In the photocatalytic results, the TiO 2 -CNTs, as compared to the pristine TiO 2 and commercial P25 TiO 2 photocatalysts, exhibited the fastest degradation performance in both dye solutions. The TiO 2 -CNTs' apparent rate constants were 0.0232 and 0.0214 min -1 in the MB and MO solutions, respectively, both of which are approximately 5 times greater than that for the commercial P25 TiO 2 (MB: 0.0046 min -1 , MO: 0.0043 min -1 ). And as for the estimated electron-transfer resistance (R ct ) results from the ac impedance spectra, the values increased in the following order: TiO 2 -CNT < P25 TiO 2 < pristine TiO 2 , indicating that CNTs can serve as electron-transmitting paths, thus suppressing the recombination rate of photogenerated electron/hole pairs. Moreover, the degree of photodegradation inhibition was insignificant in the presence of interfering anion species (1000-fold).

Enhanced Photocatalytic Degradation of Methylene Blue on Carbon Nanotube–TiO2–Pd Composites

“…19 Eighty milligrams Na 2 PdCl 4 was dissolved in 20 mL deionized water under vigorous stirring. Raw CNTs were supplied by Carbon Nano Tech.…”

“…10,11 Hybridization with sp 2 carbon structures can have beneficial effects on the photocatalytic activity of TiO 2 due to their high chemical stabilities, large surface areas, and unique electronic properties. 19 These catalysts were found to exhibit much higher photocatalytic efficiencies than the metal oxide on its own and mechanical mixtures. [12][13][14] However, the inert surface nature and strong interaction between CNTs are difficulties in dispersing nanoparticles onto CNTs, resulting in random aggregation of nanoparticles onto the CNT surface.…”

Synthesis and photocatalytic properties of three dimensional laminated structure anatase TiO2/nano-Fe0 with exposed (001) facets

“…As we all know, in the research of photocatalytic degradation of dyes, the decolorization rate is usually used as the index of photocatalytic degradation activity. [65][66][67] However, the fading of dye only means that its chromophore is destroyed, rather than it is completely mineralized into H 2 O and CO 2 . In order to evaluate the degradation efficiency of photocatalysis strictly, we studied the relationship between the decolorization rate and COD Cr removal rate.…”

Doping Transition Metals into TiO2‐CNT Nanocatalyst to Enhance the Selective Oxidation of H2S

“…Selection of suitable catalyst affects the catalysts performance in terms of sulfur yield, so it imperative synthesize catalysts with high selectivity and conversion. [3,4] Metal oxides, [5][6][7] carbon materials [8,9] and hybrid catalysts [10][11][12][13][14][15][16][17][18][19] have attracted a lot of attention as catalysts for selective oxidation of H 2 S. Moreover, doping with metallic (Nb, Ag, Pt, W, Mn, Fe, V, Mn, Co, Ni and etc. ), non-metallic (C, N, P, F, etc.)…”