All posts by Callum Tyndall

Fuel-generating photosynthetic solar cell engineered for first time

A research team at the University of Illinois, Chicago, has developed a new form of solar cell that operates on the same basis as plant photosynthesis; cheaply and efficiently converting atmospheric carbon dioxide into usable hydrocarbon fuel, with the only energy it requires coming from sunlight.

While conventional solar cells require heavy batteries to store the electricity they produce from sunlight, the new solar cell directly converts carbon dioxide into fuel. These “artificial leaves”, if in operation on a large-scale solar farm, would be able to not only provide energy-dense fuel at an efficiency far beyond that of normal cells, but also remove significant amounts of carbon from the atmosphere in the process.

“The new solar cell is not photovoltaic – it’s photosynthetic,” said Amin Salehi-Khojin, assistant professor of mechanical and industrial engineering at UIC and senior author on the study.

“Instead of producing energy in an unsustainable one-way route from fossil fuels to greenhouse gas, we can now reverse the process and recycle atmospheric carbon into fuel using sunlight.”

Amin Salehi-Khojin (left) and postdoctoral researcher Mohammad Asadi pose with the artificial leaf

Amin Salehi-Khojin (left) and postdoctoral researcher Mohammad Asadi pose with the artificial leaf

The cell produces syngas, a mixture of hydrogen gas and carbon monoxide that can either be burned directly or converted into a range of hydrocarbon fuels, including diesel. Such a process is known as a reduction reaction, as it converts CO₂ into a burnable form of carbon.

Until now producing such reactions was inefficient, and relied on expensive precious metals as catalysts.

Deciding that they required a “new family of chemicals with extraordinary properties”, Salehi-Khojin and his team selected a group of nano-structured compounds called transition metal dichalcogenides (TMDCs) to focus on. These were placed in a two-compartment, three-electrode electrochemical cell along with an unconventional ionic liquid which functioned as an electrolyte.

The purpose of this was to determine the most efficient catalyst, and it worked: the team’s ultimate choice was nanoflake tungsten diselenide, a material which was found to be 1,000 times faster and 20 times cheaper than the previously used noble-metal catalysts.

However, there was still more to do to make the process work, as on its own, the catalyst can’t survive the necessary reaction to produce fuel. The solution was to add an ionic fluid with the catchy name ethyl-methyl-imidazolium tetrafluoroborate, mixed 50-50 with water, which allows the catalyst to endure the reaction.

“The combination of water and the ionic liquid makes a co-catalyst that preserves the catalyst’s active sites under the harsh reduction reaction conditions,” Salehi-Khojin said.

A lab demonstration of the technology producing syngas when exposed to artificial sunlight. Inline images courtesy of University of Illinois at Chicago / Jenny Fontaine

A lab demonstration of the technology producing syngas when exposed to artificial sunlight. Inline images courtesy of University of Illinois at Chicago / Jenny Fontaine

The technology, which has had a provisional patent application filed, should have a fairly high rate of adaptability, as it is usable on both large and small scales. Perhaps the most exciting possibility raised, however, is usage on Mars. Given that the planet’s atmosphere is mostly carbon dioxide, if water is found, these cells could go a long way towards contributing to possible settlement on the red planet.

Robert McCabe, National Science Foundation program director, said: “The results nicely meld experimental and computational studies to obtain new insight into the unique electronic properties of transition metal dichalcogenide.

“The research team has combined this mechanistic insight with some clever electrochemical engineering to make significant progress in one of the grand-challenge areas of catalysis as related to energy conversion and the environment.”

Drone-enabled fly-fishing now a reality with DJI Phantom 4: Fishing Edition

The future has come to the forward thinking fisherman’s toolkit, in the form of the DJI Phantom 4:  Fishing Edition. While DJI’s Phantom 4 has been a huge hit, becoming one of the most popular drones of 2016, this is the first time it has been sold with custom fishing accessories included.

The package, which was created by UK drone retailer DronesDirect, includes an integrated electronic fishing spool that allows users to fish remotely, with the drone operable up to 100m above water level and up to 2km away.

Additionally, the drone contains integrated sensors to indicate when the bait has been bitten, automatic stabilisation against winds up to 20mph and a camera that allows for remote viewing of live footage. Finally, the Phantom 4 boasts a return home feature that allows it to automatically return to its commander, avoiding obstacles along the way.

“For those who enjoy fishing, the DJI Phantom 4: Fishing Edition is a bespoke package not to miss out on,” said Tim Morley, managing director at DronesDirect.

“It is a sure way to add extra excitement and an additional fun element to a great hobby, whilst allowing users to sit back, relax and reap the rewards of this drone fishing buddy.”

“The new way to fish allows users to tap into schools of fish up to 2km from shore without the use of a boat. It also enables adventurers to explore areas of sea and terrain not covered by existing maps and plans. We have enjoyed creating the perfect fisherman’s companion and are delighted to be offering this package to the public.”

drone-fishing-1

Images courtesy of DronesDirect

The price of this companion package? Just £15,000, bringing you the drone itself, along with an integrated electronic fishing spool, fishing wire and hooks, as well as the usual remote controller, battery and accessories that Phantom 4 is normally packaged with.

Whether that’s a price that many will be willing to pay remains to be seen. Drone enthusiasts have already proven that it is possible to develop home-made attachments to enable drone fishing, which suggests that while there is an interest in such a product, it may be too steep a price to match the need.

They say that if you give a man a fish, he’ll eat for a day but if you teach him to fish, he’ll eat for life. Presumably, if you teach a man to fish with a drone, he’ll make YouTube videos of it. He may however, also catch fish weighing up to 200g without ever having to stray too far from the comforts of the shore.