Titanium Oxide Nanowires In New Artificial Photosynthesis Technology Promise Cleaner Environment

By @vitthernandez on
Carbon dioxide emission
Smoke rises from a chimney of a steel plant next to residential buildings on a hazy day in Fengnan district of Tangshan, Hebei province in this February 18, 2014 file photo. Reuters/Petar Kujundzic/Files

A breakthrough technology that promises to collect carbon dioxide before it escapes the earth’s atmosphere has been successfully developed by scientists in California. The semiconducting titanium dioxide nanowires and bacteria hybrid could soon make our environment cleaner, according to the team of researchers from the U.S. Department of Energy's Lawrence Berkeley National Laboratory, the University of California, Berkeley, and the Kavli Energy NanoSciences Institute.

The collected carbon dioxide will be converted into valuable products such as alternative fuels, pharmaceutical drugs, and biodegradable plastics.

The groundbreaking invention is a revolutionary leap in the artificial photosynthesis segment. Researchers have been developing definitive solutions to various environmental concerns, including methods that aim to eliminate global warming contributors such as methane, chlorofluorocarbons, ozone, nitrous oxide and carbon dioxide from burnt fuels.

“Our system has the potential to fundamentally change the chemical and oil industry in that we can produce chemicals and fuels in a totally renewable way, rather than extracting them from deep below the ground,” research head Peidong Yang said in a report published in Nano Letters.

The system copies the natural photosynthetic process wherein plants use sunlight energy to chemically produce carbohydrates from carbon dioxide and water. However, this process utilises carbon dioxide and water to synthesise acetate, a fundamental building block for biosynthesis.

“In natural photosynthesis, leaves harvest solar energy and carbon dioxide is reduced and combined with water for the synthesis of molecular products that form biomass. In our system, nanowires harvest solar energy and deliver electrons to bacteria, where carbon dioxide is reduced and combined with water for the synthesis of a variety of targeted, value-added chemical products,” elaborated co-author Dr Christopher Chang.

The nanowire-bacteria hybrid system can convert solar energy at an efficiency of around 0.38 percent under simulated sunlight. This is around the same level as that of a natural leaf.

Today, the scientists are still focused on improving the system. They are now currently working on a second-generation model that uses solar-to-chemical conversion with three percent efficiency rate. However, the technology can only be commercially viable if it reaches 10 percent efficiency rate, Yang admitted.

The commercialisation of the system could possibly increase the demand for titanium dioxide, especially for its principal sources such as rutile and ilmenite.

Today, the largest consumer of titanium dioxide is the paints and coatings industry. It is widely used as a colouring agent in steel and copper alloy products. Demand for titanium is stable, although the supply segment is currently precarious. 

Rutile supply from the African region, one of the largest sources in the world, is expected to decline due to Ebola-related concerns, though it will be mitigated by newcomers in the mining sector like White Mountain Titanium Corporation (OTCQB:WMTM).

The company is behind the Cerro Blanco Property, a 17,041 hectares rutile deposit in Santiago, Chile. According to the experts, it is one of the largest titanium dioxide facilities in the world today, and a key entity in stabilising the demand segment. The property is capable of producing up to 112 million tonnes of rutile. 

Currently, the global titanium dioxide market is valued at $13.14 billion in 2013 and is expected to reach $17.12 billion by 2020. 

To contact the writer, email: v.hernandez@ibtimes.com.au

Join the Discussion