/ 31 []


Introduction. Photocatalysis - Need of the day . . Photocatalysis. . . Photocatalytic Applications. Antimicrobial Effect. . Antimicrobial Effect. . Self-Cleaning Effect. . . . . Photocatalysts. TiO2

Download Presentation


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use only and may not be sold or licensed nor shared on other sites. SlideServe reserves the right to change this policy at anytime.While downloading, If for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript

Tio 2 green catalyst clean environment l.jpg


Dr. Romana Khan

Department of Environmental Sciences, COMSATS Institute of Information Technology, Abbottabad

1st National Conference on Biotechnology & Microbiology

Introduction l.jpg


Photocatalysis - Need of the day

Photocatalysis l.jpg

CO2 + H2O






+ H2O + O2


Starch + O2

Organic compound


Photocatalytic applications l.jpg

Photocatalytic Applications

Antimicrobial effect l.jpg

Antimicrobial Effect

Slide6 l.jpg

Antimicrobial Effect

Self cleaning effect l.jpg

Self-Cleaning Effect

Photocatalysts l.jpg


Tio 2 an ideal photocatalyst l.jpg

TiO2 – an Ideal Photocatalyst

  • Cheap and can be reused

  • High photo-chemical corrosive resistance

  • Strong oxidizing power

  • Photocatalysis takes place at ambient temperature

  • Atmospheric oxygen is used for the reaction

Tio 2 photocatalysis l.jpg

TiO2 - Photocatalysis

3.12 eV (380 nm)

Redox potential of h l.jpg

Redox potential of h+

  • The redox potential for photogenerated h+ is +2.53 V vs. the SHE

  • After reaction with water, these h+ can produce •OH

  • Both h+ and •OH are more positive compare to ozone

Photocatalytic reactions l.jpg

Photocatalytic Reactions

Entail physicochemical properties of tio 2 l.jpg

Entail Physicochemical Properties of TiO2

The applications of TiO2 is a function of specific physicochemical properties like:

  • High Surface area

  • Small Crystalline Size

  • Anatase form of TiO2

  • High crystallinity

  • Porous structure

  • Activation light source

    An appropriate synthetic procedure can provide TiO2 with promising efficiency

Synthesis of tio 2 powders l.jpg

Synthesis of TiO2 Powders

Synthesis of TiO2 powders

  • Sulfate Method

  • Chloride Method

  • Specific Methods

  • Sol-Gel Method

Slide16 l.jpg

Hydrolysis and Condensation

Sol gel technology l.jpg

Sol-Gel Technology

Vi sible light active photocatalyst l.jpg

Visible-Light Active Photocatalyst

TiO2– efficient photocatalyst under UV light

Yet, need visible-light active photocatalyst for practical purpose

Can be achieved by doping TiO2 with nonmetals, transition metals and dyes

Activity increases by loading a metaloxide

Metal oxide reduces the chance of recombination of electrons & holes produced during photocatalytic reactions

Modification of tio 2 l.jpg

Modification of TiO2

Coating techniques l.jpg

Coating Techniques

A- Spin Coating Method

Slide21 l.jpg

B- Dip Coating Method

C spray coating method l.jpg

C-Spray Coating Method

D sputtering method l.jpg

Setting SubstratesVacuumingCoating/ Discharging plasmaCollecting Substrates

D- Sputtering Method

E plate coating l.jpg

E- Plate Coating

An acid base catalyzed sol gel synthesis of tio 2 photocatalysts l.jpg

An Acid-Base Catalyzed Sol-Gel Synthesis of TiO2 Photocatalysts

Ti(OBu)4 + EtOH

HCl + H2O + EtOH

Stirring (12 h)

Sol (pH 0.8)

Stirring (12 h)


Gel (pH 9.0 )

Drying (1100C, 12 h)


Phase structure and thermal stability l.jpg

Phase Structure and Thermal Stability

XRD patterns of TiO2 samples; (a) as-dried, and calcined at (b) 350 oC, (c) 400 oC, (d) 500 oC, (e) 600 oC and (f) 800oC.

Some selected properties of tio 2 powders l.jpg

Some Selected Properties of TiO2 Powders

Photocatalytic efficiency l.jpg

Photocatalytic Efficiency

  • Catalytic degradation of toluene by different TiO2 samples;

  • Blank (■)(b)TiO2 – as-dried (●); (c) P-25 (▲); and TiO2 calcined at

  • (d) 350oC (▼); (e) 400oC () (f) 500oC (◄ ); (g) 600oC (►).

Photoreactor l.jpg


Slide30 l.jpg


  • Romana Khan, S.W. Kim, T.J. Kim, H.S. Lee – A novel acid-base catalyzed sol-gel synthesis of highly active mesoporous TiO2 photocatalysts, Bulletin of the Korean Chemical Society, 28(11), 1951-1957 (2007).

  • Romana Khan, S.W. Kim, T.J. Kim – Synthesis and control of physical properties of titania nanoparticles as a function of synthetic parameters, Journal of Nanoscience and Nanotechnology, 8(9), 4738-4742 (2008).

  • Romana Khan, S.W. Kim, T.J. Kim, C.M. Nam – Comparative study of the photocatalytic performance of boron–iron co-doped and boron-doped TiO2 nanoparticles, Materials Chemistry and Physics, 112(1), 167-172 (2008).

  • Romana Khan, S.W. Kim, T.J. Kim, C.M. Nam – Comparative study of the photocatalytic performance of boron–iron co-doped and boron-doped TiO2 nanoparticles, Materials Chemistry and Physics, 112(1), 167-172 (2008).

  • Romana Khan, T.J. Kim – Preparation and application of visible-light responsive Ni-doped and SnO2-coupled TiO2 nanocomposite photocatalysts, Journal of Hazardous Materials, 163(2-3), 1179-1184 (2009).

Slide31 l.jpg

Thank You