Featured Research

from universities, journals, and other organizations

New visible light photocatalyst kills bacteria, even after light turned off

Date:
January 20, 2010
Source:
University of Illinois at Urbana-Champaign
Summary:
In the battle against bacteria, researchers have developed a powerful new weapon -- an enhanced photocatalytic disinfection process that uses visible light to destroy harmful bacteria and viruses, even in the dark.

Jian Ku Shang, a professor of materials science and engineering, holds a sample of a new photocatalytic material that uses visible light to destroy harmful bacteria and viruses, even in the dark.
Credit: Photo by L. Brian Stauffer

In the battle against bacteria, researchers at the University of Illinois have developed a powerful new weapon -- an enhanced photocatalytic disinfection process that uses visible light to destroy harmful bacteria and viruses, even in the dark.

Based upon a new catalyst, the disinfection process can be used to purify drinking water, sanitize surgical instruments and remove unwanted fingerprints from delicate electrical and optical components.

"The new catalyst also has a unique catalytic memory effect that continues to kill deadly pathogens for up to 24 hours after the light is turned off," said Jian Ku Shang, a professor of materials science and engineering at the U. of I.

Shang is corresponding author of a paper that is scheduled to appear in the Journal of Materials Chemistry, and posted on the journal's website.

Shang's research group had previously developed a catalytic material that worked with visible light, instead of the ultraviolet light required by other catalysts. This advance, which was made by doping a titanium-oxide matrix with nitrogen, meant the disinfection process could be activated with sunlight or with standard indoor lighting.

"When visible light strikes this catalyst, electron-hole pairs are produced in the matrix," Shang said. "Many of these electrons and holes quickly recombine, however, severely limiting the effectiveness of the catalyst."

To improve the efficiency of the catalyst, Shang and collaborators at the U. of I. and at the Chinese Academy of Sciences added palladium nanoparticles to the matrix. The palladium nanoparticles trap the electrons, allowing the holes to react with water to produce oxidizing agents, primarily hydroxyl radicals, which kill bacteria and viruses.

When the light is turned off, the palladium nanoparticles slowly release the trapped electrons, which can then react with water to produce additional oxidizing agents.

"In a sense, the material remembers that it was radiated with light," Shang said. "This 'memory effect' can last up to 24 hours."

Although the disinfection efficiency in the dark is not as high as it is in visible light, it enables the continuous operation of a unique, robust catalytic disinfection system driven by solar or other visible light illumination.

In addition to environmental applications, the new catalyst could also be used to remove messy, oily fingerprints from optical surfaces, computer displays and cellphone screens, Shang said.

The work was supported by the National Science Foundation through the Center of Advanced Materials for the Purification of Water with Systems at the U. of I. Some of the work was performed at the U. of I.'s Frederick Seitz Materials Research Laboratory, which is partially supported by the U.S. Department of Energy.


Story Source:

The above story is based on materials provided by University of Illinois at Urbana-Champaign. Note: Materials may be edited for content and length.


Cite This Page:

University of Illinois at Urbana-Champaign. "New visible light photocatalyst kills bacteria, even after light turned off." ScienceDaily. ScienceDaily, 20 January 2010. <www.sciencedaily.com/releases/2010/01/100119121539.htm>.
University of Illinois at Urbana-Champaign. (2010, January 20). New visible light photocatalyst kills bacteria, even after light turned off. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2010/01/100119121539.htm
University of Illinois at Urbana-Champaign. "New visible light photocatalyst kills bacteria, even after light turned off." ScienceDaily. www.sciencedaily.com/releases/2010/01/100119121539.htm (accessed July 25, 2014).

Share This




More Matter & Energy News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Europe's Highest Train Turns 80 in French Pyrenees

Europe's Highest Train Turns 80 in French Pyrenees

AFP (July 25, 2014) Europe's highest train, the little train of Artouste in the French Pyrenees, celebrates its 80th birthday. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
TSA Administrator on Politics and Flight Bans

TSA Administrator on Politics and Flight Bans

AP (July 24, 2014) TSA administrator, John Pistole's took part in the Aspen Security Forum 2014, where he answered questions on lifting of the ban on flights into Israel's Tel Aviv airport and whether politics played a role in lifting the ban. (July 24) Video provided by AP
Powered by NewsLook.com
Creative Makeovers for Ugly Cellphone Towers

Creative Makeovers for Ugly Cellphone Towers

AP (July 24, 2014) Mobile phone companies and communities across the country are going to new lengths to disguise those unsightly cellphone towers. From a church bell tower to a flagpole, even a pencil, some towers are trying to make a point. (July 24) Video provided by AP
Powered by NewsLook.com
Algonquin Power Goes Activist on Its Target Gas Natural

Algonquin Power Goes Activist on Its Target Gas Natural

TheStreet (July 23, 2014) When The Deal's Amanda Levin exclusively reported that Gas Natural had been talking to potential suitors, the Ohio company responded with a flat denial, claiming its board had not talked to anyone about a possible sale. Lo and behold, Canadian utility Algonquin Power and Utilities not only had approached the company, but it did it three times. Its last offer was for $13 per share as Gas Natural's was trading at a 60-day moving average of about $12.50 per share. Now Algonquin, which has a 4.9% stake in Gas Natural, has taken its case to shareholders, calling on them to back its proposals or, possibly, a change in the target's board. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins