During photosynthesis, plants capture solar energy and use it to drive chemical reactions. Their carbon source is the CO2 in air. In the journal Angewandte Chemie, American scientists have now proposed a new reaction mechanism that binds CO2 and strongly resembles photosynthesis.
In this process, light energy is captured by silicon nanowires. It was successfully used to synthesize two precursors of the anti-inflammatory, pain reducing drugs ibuprofen and naproxen.
Natural photosynthesis involves two processes, the light and dark reactions. In the light reactions, photons are captured and their energy stored in the form of chemical compounds like NADPH (nicotinamide adenine dinucleotide phosphate) and ATP (adenosine triphosphate), which subsequently are used to bind CO2 for the synthesis of complex sugar molecules. At the heart of the dark reactions is the binding of CO2 to a sugar phosphate (ribulose-1,5-bisphosphate). This results in formation of a â–keto acid, which gets converted to a central building block for sugar synthesis.
A team led by Kian L. Tan and Dunwei Wang at Boston College (Chestnut Hill, USA) has been inspired by the mechanisms of the dark reactions. To capture sunlight, the scientists used p-doped silicon nanowires as a photocathode. These very effectively convert solar energy to electrical energy, are easy to produce, and are amazingly stable under the reaction conditions needed. Captured photons release electrons from the atoms in the nanowires.
These electrons can easily be transferred to organic molecules to trigger chemical reactions. The researchers chose aromatic ketones as their starting materials. Transfer of electrons from the photocathode “activates” these molecules so that they can attack and bind CO2. Over several steps, the reaction produces an á-hydroxy acid.
This allowed the team to produce precursors of ibuprofen and naproxen with high selectivity and in high yield.
This reaction sequence closely resembles natural photosynthesis and is completely different from previous approaches to binding CO2 with the aid of sunlight. This finally solves a problem: The very poor selectivity that automatically accompanies all traditional attempts at the direct photoreduction of CO2 has limited previous methods to the production of fuels. This new strategy delivers the selectivity required for the production of complex organic intermediates for the production of pharmaceuticals and high-value fine chemicals.About the Author
Author: Dunwei Wang, Boston College, Chestnut Hill (USA), https://www2.bc.edu/~dwang/Title: Silicon Nanowires as Photoelectrodes for Carbon Dioxide Fixation
Make way for the mini flying machines
21.03.2018 | American Chemical Society
New 4-D printer could reshape the world we live in
21.03.2018 | American Chemical Society
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.
In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
19.03.2018 | Event News
16.03.2018 | Event News
13.03.2018 | Event News
21.03.2018 | Physics and Astronomy
21.03.2018 | Materials Sciences
21.03.2018 | Life Sciences