photocatalytic activity of macroporous ti o2 p25 films

Macro-porous TiO2-P25 composite thick film for

photocatalytic applications

Dr. Hazem Falah Sakeek

Department of Physics

Al-Azhar University - Gaza

المؤتمر الدولي الثاني

للعلوم األساسية والتطبيقية

The Second International Conference on

Basic and Applied Sciences

Oct 9 – 11, 2012

Institute for Materials & Surface

Technology (IMST)

Kiel – Germany

Sponsored by DAAD

The objectives of this research work are:

(1) to use sol-gel technique to produce a macro-porous

TiO2-P25 composite films.

(2) to evaluate the photocatalytic activity of the fabricated

TiO2-P25 composite films.

Dr. Hazem Falah Sakeek 2

Introduction

Environmental contamination, which is growing around the

world or in our daily life, is a serious social problem not to be

neglected.

Examples of such contamination can be endlessly listed as

follows:

— Water pollution caused by industrial and household wastes

— Respiratory diseases caused by air pollutants such as SOx or

NOx

— Room air contamination caused by organic compounds

emerging from newly developed building materials


Solution for the Environmental contamination

The fact that using energy to eliminate such environmental

contamination increases emission of CO2 resulting in more global

warming, however, leads us to a dilemma not to use energy to

achieve our anti-pollution goal.

We need a new method that can gently harmonize the contaminated

environment to restore original conditions by using natural energy.

One solution to that problem is, Photo-catalyst.


What is a photo-catalysts?

Catalyst is a substance that makes a chemical reaction more likely to happen by

reducing the activation energy needed to start it.

A catalyst speed up a chemical reaction or make it happen at a lower temperature.

Once the reaction has finished, the catalyst isn't used up.

Photocatalysis means light is involved in making a catalyst do its job. In other

words, light provides the energy that allows the catalyst to work.


The function of the photo-catalyst are:

Purifying water

Preventing contamination (Sterilization)

Purifying the air

(dissolving NOx)

Deodorizing

Anti-bacteria


Thin-film Photocatalyst

In order to use TiO2 as an effective photocatalyst for the

above mentioned applications, powder is not an appropriate

form, because it may be blown off by wind or washed out by

water, and when used to purify water, it has to be separated

from the water. Thus, a method to fix the powder is required.


Film Preperation

Material Used

Titanium (IV) Isopropoxide,

Diethanolamine (DEA) as a

stabilizing agent,

Nanocrystalline TiO2 Titanium

Powder P25, used as filler

Acetyl acetone,

Ethanol,

Polyethylene glycol (PEG 400)

used as a surfactant.

Method

Films prepared by spin-coating at

3000rpm for 20s on a glass

substrate. And annealed at 400oC

for 10min.


Characterization

XRD

SEM

Optical Properties Measurements for

the films

UV-Visible Absorption of MO for

Photocatalyst activity.


XRD Spectra for TiO2, P25 Thin films


XRD patterns of TiO2-P25 composite films calcinated at 400oC

10%w PEG

Without using PEG


Numerous random macropores are formed through the nanoscale TiO2 particles

Photocatalysis Measurements

Visual degradation of the MO dye

15

UV-VIS Absorption Spectra of MO

Absorption spectra of MO dye sol illuminated by UV radiation in

contact with TiO2-P25 films as a function of time


tkA

ALn

o

Variation of Ln(A/Ao) of MO dye solution in contact with TiO2-P25 composite

film as a function of illumination period at wavelength of 463nm.

Photocatalytic activity for TiO2-P25 Film


Conclusion

Macroporous TiO2-P25 composite films have been successfully Fabricated

on glass substrate by spin-coating techniques free of cracks and

agglomeration.

The photocatalytic behavior of the films have been investigated.

Future Work

Optimize the P25 loading and study its effect on the photocatalyst.

Study the effect of the film structure (porous size) on the photocatalyst.

Modifying the Film with Noble metals such as Ag, Au, Pt. to extend the

Photocatalyst in the visible region of the spectrum.


photocatalytic activity of macroporous ti o2 p25 films

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