An Investigation into W or Nb or ZnFe2O4 Doped Titania Nanocomposites Deposited from Blended Powder Targets for UV/Visible Photocatalysis

Abstract

Abstract:The photocatalytic behavior of titania coatings is largely determined by their crystalline structure. Depending on deposition conditions, though, titania may form amorphous, brookite, anatase or rutile structures, with anatase or anatase/rutile mixed phase structures showing the highest levels of activity. Anatase is activated by UV light and, consequently, there is a great deal of interest in doping titania films to both increase activity and extend it into the visible range. In this study, titania and doped titania coatings have been deposited from blended oxide powder targets. This highly versatile and economical technique allows dopant levels to be readily varied. Using this technique, titania coatings doped with W, Nb and ZnFe2O4 have been deposited onto glass substrates by pulsed magnetron sputtering. The as-deposited coatings were analyzed by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and micro-Raman spectroscopy. Selected coatings were then annealed at temperatures in the range of 400-700 °C and re-analyzed. Structural transformation of the titania coatings was initiated in the 500-600 °C range, with the coatings annealed at 700 °C having predominantly anatase structures. The photocatalytic activity of the coatings was assessed through OPEN ACCESSCoatings 2013, 3 154 measurements of the degradation of organic dyes, such as methyl orange, under the influence of UV and fluorescent light sources. It was found that, after annealing, coatings with photo-active surfaces were produced and that activity varied with dopant content. Activity levels under fluorescent light irradiation were up to 60% of the activity measured under UV irradiation.

Formation of TiO2 nanostructures modified Eumelanin films with enhanced properties for biopolymer implementations

“…7(a) that indicates the presence of TiO 2 nanoparticles modes in the range of 400-900 cm -1 . The spectrum exhibit Raman fingerprints for anatase phase with important modes B 1g (419 cm -1 ), A 1g (517 cm -1 ) and E g (639 cm -1 ) in agreement with previous results [40].…”

Microwave Synthesis of Visible-Light-Activated g-C3N4/TiO2 Photocatalysts

“…The produced nanomaterials in powder form were tested as photocatalysts for the degradation of MO under solar simulating light. The degradation rate was monitored by recording the decay in the absorbance peak intensity at 464 nm [ 112 ] using a UV-VIS spectrophotometer in intervals of 30 min (for the first 2 h) and every 1 h up to 240 min (4 h) subsequently ( Figure S3a–e ). After this time, a transparent solution could be observed ( Figure S3f ).…”

Superhydrophobic photocatalytic PTFE – Titania coatings deposited by reactive pDC magnetron sputtering from a blended powder target

“…Thus, unlike the sputter targets used in RF magnetron sputtering, the target generally requires significant conductivity, therefore the choice of materials to be sputtered is limited. However, the use of loosely packed (not sintered) blended powder targets helps to overcome materials limitations and enables simple control of coating composition by varying the ratio of materials in the powder target [24][25][26][27]. This method has been reported to produce photocatalytic coatings with the activities similar to the ones produced by conventional sputtering techniques [28].…”