Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Surface Modification of TiO2 for Photocatalytic Degradation of Hazardous Pollutants Under Ordinary Visible Light

22.04.2014

UiTM researchers have developed a modified photocatalyst which is economical and effective at transforming organic pollutants into harmless end products.

Photocatalytic degradation is one of the highly effective applications in transforming organic pollutants to harmless end products at ambient conditions using light and a photocatalyst.

Titanium dioxide (TiO2) is the most commonly used photocatalyst in many environmental applications but it can be used only under UV light owing to its high band gap energy (3.2 eV). UV light being energy intensive, it makes the photocatalytic degradation process very expensive.

In solar light spectrum, UV light exists only within 3-5% compared to visible light (45%). Therefore, for practical application, it is highly desirable to develop TiO2 photocatalyst which can effectively degrade the pollutants under visible light irradiation.

Various techniques proposed in the literature to extend the absorption wavelength from UV to visible light region include semiconductor coupling, metal doping, dye sensitising and doping with nonmetal elements.

The most feasible method to modify the structure of photocatalyst is by doping with nonmetal, since it narrows down the band gap besides being stable, inexpensive and non photo corrosive. Doping with nitrogen attracted huge attention due to its high visible light active photocatalytic efficiency. Other nonmetal elements commonly used as dopants include iodine, carbon, sulphur and boron.

Nitrogen (N) and carbon (C) were selected as dopants in this study because they both could prevent the electron-hole pair from recombination during the photodegradation (how).

We developed a modified photocatalyst which has desirable properties such as economical, environmental friendly, structural stability and high degradation rate by a simple preparation method after carefully studying the effects of dopant concentration and calcination temperature (advantages).

Application of this catalyst will ensure higher degradation rate of volatile organic compounds (carcinogenic) at lower cost leading to pollution free environment (socio economy impact).

This material will be of great help to the Petrochemical, Oil and gas industries to implement a low cost technology for the removal of organic pollutants at their premises (commercialisation potential). Elemental doping of titanium dioxide with nitrogen and carbon was investigated in this study to get the modified photocatalyst working under visible light.

Doped and codoped photocatalyst samples were synthesized by solgel method using titanium isopropoxide, ammonium nitrate and acetylacetone as precursors with the dopant concentration and calcination temperature fixed at 0.75% and 600oC respectively.

Synthesized photocatalysts were characterized by XRD, FTIR and FESEM which supported the existence of anatase phase, presence of dopants and formation of fine particles respectively.

Theoretically photocatalytic activity is affected by many factors such as phase structure, crystallinity, surface hydroxyl density and oxygen vacancies. The highest photocatalytic activity was observed for N-C-TiO2. In 3 hours, the degradation was 91.3%.

This might be attributed to combined effect of the phase structure, particle size and the component existed in the photocatalyst. Strong anatase peaks as observed in XRD represented strong interaction of all the doped elements with TiO2 surfaces, which resulted in higher photocatalytic degradation.

Particle size also facilitated the photocatalytic reaction. Finer the size, higher is the photocatalytic performance which was well supported by the results from FESEM. The hydroxyl group presented in the photocatalyst as discussed in FTIR also contributed to the increased photocatalytic activity.

This novel material finds a solution to replace the use of high energy intensive UV radiation for the treatment of gaseous and aqueous pollutants with just with the ordinary domestic lamps to convert them into harmless end products (ecofriendly) thereby greatly reducing the total cost of waste management (economical).

For more information, contact
JAGANNATHAN KRISHNAN
UNIVERSITI TEKNOLOGI MARA
SELANGOR
FACULTY OF CHEMICAL ENGINEERING
jagannathann@salam.uitm.edu.my

Darmarajah Nadarajah | Research SEA News
Further information:
http://www.uitm.edu.my

Further reports about: FTIR Particle Petrochemical Surface TiO2 Visible activity anatase degradation energy hydroxyl prevent temperature titanium

More articles from Power and Electrical Engineering:

nachricht Transforming waste heat directly into electricity
03.05.2016 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH

nachricht Did you know that Heraeus PID lamps have been used in the measurement of air quality at the London airport?
02.05.2016 | Heraeus Noblelight GmbH

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Nuclear Pores Captured on Film

Using an ultra fast-scanning atomic force microscope, a team of researchers from the University of Basel has filmed “living” nuclear pore complexes at work for the first time. Nuclear pores are molecular machines that control the traffic entering or exiting the cell nucleus. In their article published in Nature Nanotechnology, the researchers explain how the passage of unwanted molecules is prevented by rapidly moving molecular “tentacles” inside the pore.

Using high-speed AFM, Roderick Lim, Argovia Professor at the Biozentrum and the Swiss Nanoscience Institute of the University of Basel, has not only directly...

Im Focus: 2+1 is Not Always 3 - In the microworld unity is not always strength

If a person pushes a broken-down car alone, there is a certain effect. If another person helps, the result is the sum of their efforts. If two micro-particles are pushing another microparticle, however, the resulting effect may not necessarily be the sum their efforts. A recent study published in Nature Communications, measured this odd effect that scientists call “many body.”

In the microscopic world, where the modern miniaturized machines at the new frontiers of technology operate, as long as we are in the presence of two...

Im Focus: Tiny microbots that can clean up water

Researchers from the Max Planck Institute Stuttgart have developed self-propelled tiny ‘microbots’ that can remove lead or organic pollution from contaminated water.

Working with colleagues in Barcelona and Singapore, Samuel Sánchez’s group used graphene oxide to make their microscale motors, which are able to adsorb lead...

Im Focus: ORNL researchers discover new state of water molecule

Neutron scattering and computational modeling have revealed unique and unexpected behavior of water molecules under extreme confinement that is unmatched by any known gas, liquid or solid states.

In a paper published in Physical Review Letters, researchers at the Department of Energy's Oak Ridge National Laboratory describe a new tunneling state of...

Im Focus: Bionic Lightweight Design researchers of the Alfred Wegener Institute at Hannover Messe 2016

Honeycomb structures as the basic building block for industrial applications presented using holo pyramid

Researchers of the Alfred Wegener Institute (AWI) will introduce their latest developments in the field of bionic lightweight design at Hannover Messe from 25...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

The “AC21 International Forum 2016” is About to Begin

27.04.2016 | Event News

Soft switching combines efficiency and improved electro-magnetic compatibility

15.04.2016 | Event News

Grid-Supportive Buildings Give Boost to Renewable Energy Integration

12.04.2016 | Event News

 
Latest News

New fabrication and thermo-optical tuning of whispering gallery microlasers

04.05.2016 | Physics and Astronomy

Introducing the disposable laser

04.05.2016 | Physics and Astronomy

A new vortex identification method for 3-D complex flow

04.05.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>