Preparation of Photocatalytic Titania on OrganicSupport via Sol-Gel Method for Water Clarification


Erdem İ.

20th International Sol-Gel Conference, Sankt-Peterburg, Rusya, 25 - 30 Ağustos 2019, ss.222

  • Basıldığı Şehir: Sankt-Peterburg
  • Basıldığı Ülke: Rusya
  • Sayfa Sayısı: ss.222

Özet

The water is an important resource for life which should be recycled. The recycling of water is getting more difficult with the industrialization and release of versatile pollutants in big

quantities. There are research activities to create new methodology for clarification of resistant pollutants, which are hard to remove. An alternative method is to oxidize these pollutants via

photocatalytic oxidation. Titania (TiO2) has photocatalytic activity that it may be used for the clarification purpose. The previous research reported that the titania has a higher catalytic efficiency

with decreasing particulate size. Using sol-gel method is promising to have submicron titania particulates with high photocatalytic activity. The crystal morphology of titania was also reported to

be effective on its photocatalytic activity. The anatase phase and/or mixture anatase & rutile phases were reported to have higher catalytic activity. The sol-gel method enables preparation of titania

with controlled crystal morphology that will enable preparation of photocatalytic titania with relatively higher efficiency. The efficiency of photocatalytic activity of titania was also tried to be

enhanced via decreasing its energy band gap for excitation, which will make it sensitive to radiations with relatively lower energy (i.e. higher wave length). For this purpose different elements (e.g. Fe,

Ni, Au, S, N, C, etc.) were doped in titania, or some dyes were used to make it photocatalytically active under visible light (instead of ultraviolet (UV) light which has higher energy but is with limited

ratio in sunlight). In present work sol-gel method was used to prepare nano/submicron-titania on organic supports using titanium isopropoxide. The organic supports were ground nut shell powder

(e.g. walnut) which are waste/side products. The photocatalytic activity of organic supported submicron titania catalyst was determined via oxidation of dyes (e.g. methylene blue) under

excitation via UV and/or visible light and it was compared with activity of commercial nano titania powder. Higher efficiencies were obtained by using the prepared organic supported titania catalyst

which may have relatively lower cost than the commercial nano titania powder. The particle size distribution (PSD) analysis was performed via laser light scattering technique and average particle

sizes of a few nanometers were measured for the sols preparerd. The prepared catalyst using the sols and the fine (ground) powder of nut shells was characterized via SEM (scanning electron

microscope) and XRD (X-ray diffraction). Research continues on possible enhancements for photocatalytic activity of the prepared catalyst, which already has promising efficiency for

clarification of water. The utilization of prepared organic supported titania catalyst may also be possible for some other applications.