Vanadium oxides doped porous titania photocatalyst for phenol photodegradation

Abstract

Two series of new porous photocatalysts of vanadium oxides (1 - 5 wt%) doped porous TiO2 using tetrabutyl titanate (TBT) and titanium tetraisopropoxide (TTIP) as Ti precursor were successfully synthesized. The photocatalysts were synthesized via sol-gel method using cetyltrimethylammonium bromide (CTAB) as template. X-ray diffraction analysis showed that all the photocatalysts crystallined in anatase phase. There was no CTAB residue in the photocatalyst synthesized after calcination at 773 K. According to diffused reflectance UV-visible spectroscopy analysis, the band gap energy reduced from 3.02 (in TBT-TiO2) to 2.72 eV (in 5V-TBT-p-TiO2) for TiO2 synthesized using TBT as Ti precursor. Similarly, reduction in band gap energy from 3.11 (in TTIP-TiO2) to 2.66 eV (in 5V-TTIP-p-TiO2) for TiO2 synthesized using TTIP as Ti precursor. The nitrogen adsorption-desorption analysis revealed that the surface area of both series increased with the amount of dopant. These materials contained of disorder mesopores with particle size range of 5 – 56 nm. The photocatalytic testing results showed that samples 4V-TBT-p-TiO2 and 4V-TTIP-p-TiO2 recorded the highest percentage of phenol degradation under visible light irradiation in their respective series. Sample 4V-TBT-p-TiO2 photodegraded 62.2% phenol, while 4V-TTIP-p-TiO2 photodegraded 62.8% phenol after 7 h reaction time. There was no significant difference between the photodegradation performances of two series of vanadium oxide doped TiO2.