Tag Archives: chemicals

Harnessing light for a solar-powered chemical industry

RMIT University researchers have developed a nano-enhanced material that can capture an incredible 99% of light and convert it to power chemical reactions.

As well as reducing the environmental impact of chemical manufacturing, the innovation could one day be used to deliver technologies like better infrared cameras and solar-powered water desalination.

Published today in ACS Applied Energy Materials, the research addresses the challenge of finding alternative energy sources for chemical manufacturing, which accounts for about 10% of global energy consumption and 7% of industrial greenhouse gas emissions.

In the US, chemical manufacturing uses more energy than any other industry, accounting for 28% of industrial energy consumption in 2017.

While photo catalysis – the use of light to drive chemical reactions – is growing in the industry, efficiency and cost remain significant obstacles to wider take-up.

Lead investigator Associate Professor Daniel Gomez said the new technology maximised light absorption to efficiently convert light energy into chemical energy.

“Chemical manufacturing is a power hungry industry because traditional catalytic processes require intensive heating and pressure to drive reactions,” Gomez, an ARC Future Fellow in RMIT’s School of Science, said.

“But one of the big challenges in moving to a more sustainable future is that many of the materials that are best for sparking chemical reactions are not responsive enough to light.”

“The photo catalyst we’ve developed can catch 99% of light across the spectrum, and 100% of specific colours.

“It’s scaleable and efficient technology that opens new opportunities for the use of solar power – moving from electricity generation to directly converting solar energy into valuable chemicals.”

Nano-tech for solar power

The research focused on palladium, an element that’s excellent at producing chemical reactions but usually not very light responsive.

By manipulating the optical properties of palladium nanoparticles, the researchers were able to make the material more sensitive to light.

While palladium is rare and expensive, the technique requires just a miniscule amount – 4 nanometres of nano-enhanced palladium is enough to absorb 99% of light and achieve a chemical reaction. An average human hair, for comparison, is 100,000 nanometres thick.

Daniel Gomez with a disc covered in the nano-enhanced palladiumARC Future Fellow, Associate Professor Daniel Gomez, holding a disc covered in the nano-enhanced palladium (Image: RMIT).

 

Beyond chemical manufacturing, the innovation could be further developed for a range of other potential applications including better night vision technology by producing more light-sensitive and clearer images.

Another potential use is for desalination. The nano-enhanced material could be put in salty water then exposed to sunlight, producing enough energy to boil and evaporate the water, separating it from the salt.

Gomez, who leads the Polaritonics Lab at RMIT, said the new technology could significantly increase the yield in the emerging photo-catalysis sector, with leading firms currently producing about 30kg of product each day using light as the driving force.

“We all rely on products of the chemical manufacturing industry – from plastics and medicines, to fertilisers and the materials that produce the colours on digital screens,” he said.

“But much like the rest of our economy, it’s an industry currently fuelled by carbon.

“Our ultimate goal is to use this technology to harness sunlight efficiently and convert solar energy into chemicals, with the aim of transforming this vital industry into one that’s renewable and sustainable.”

The research, with collaborators from CSIRO, the Melbourne Centre for Nanofabrication and University of Melbourne, is published in ACS Applied Energy Materials (DOI: 10.1021/acsaem.8b01704).

A paper demonstrating similar technology using gold nanoparticles will be published in a forthcoming edition of the journal ACS Photonics.

Gosia Kaszubska

This article was originally published by RMIT.

Taming toxic pollution

CRC CARE is addressing the significant growing issue of toxic environmental pollution with innovative and effective real-world solutions.

Recently, major concerns have emerged across Australia about sites contaminated by chemical pollutants known as per- and poly-fluoroalkyl substances (PFAS).

Potentially harmful to human health and the environment, some PFAS are active ingredients in firefighting foam. These include PFOS, which is listed in the Stockholm Convention on Persistent Organic Pollutants. PFAS contamination has become a big problem near some firefighting training areas, where it has contaminated soil and water.

“There are more than 100,000 potentially toxic chemicals and five million potentially contaminated sites globally, so there is a real need for innovation,” says Professor Ravi Naidu, CEO of the CRC for Contamination Assessment and Remediation of the Environment (CRC CARE).

One of CRC CARE’s innovations is a product called matCARE, a modified natural clay that can irreversibly lock up PFAS so polluted soil and water can be decontaminated. Naidu says matCARE is 50% more efficient – and thus cheaper – than similar technologies, and does not leach PFAS over time.

Four firefighting training sites have successfully cleaned up the pollution with matCARE and CRC CARE is now looking to partner with companies to broaden its use beyond the safe storage of the chemical. “The technology that’s available at the moment can only immobilise PFAS and unfortunately there is still a contaminated product at the end,” explains Naidu. “We have developed a technology that breaks down PFAS into carbon dioxide and fluoride. Companies are looking for technology that decomposes PFAS into safe products and we have been able to do that.”

Cherese Sonkkila

crccare.com