Transition metal–catalyzed arylation of C–H bonds has been intensively studied for forming C–C bonds in complex-molecule synthesis (1). An acidic C–H bond (for example, one near a double bond or an O atom) is cleaved to form a carbon–metal bond, which then couples to arene. Many of these organometallic species can be generated catalytically. Much less research has dealt with unreactive nonacidic sp3 C–H bond functionalization (3). On page 1304 of this issue, Shaw et al. (3) report an efficient and general method that focuses on arylation of sp3 C–H bonds at carbon atoms adjacent to amines and to cyclic ethers by combining nickel, visible-light photoredox, and hydrogen-atom transfer (HAT) catalysis.
Plants use sunlight to turn carbon dioxide and water into glucose. In the same way, artificial leaves use the sun's energy to turn carbon dioxide and water into hydrocarbon fuels. Using sunlight to split water into hydrogen and oxygen, scientists have developed a catalyst called'nanoflake tungsten diselenide'. This catalyst converts carbon monoxide in a leaf at greatly improved efficiency compared with conventional metal catalysts. When combined with the hydrogen the carbon monoxide produces a fuel called syngas that can then be used as the basis of hydrocarbons.
In the new study, the researchers dropped the full experimental set up for photocatalysis down a 120m drop tower, creating an environment similar to microgravity. As objects accelerate towards Earth in free fall, the effect of gravity diminishes as forces exerted by gravity are cancelled out by equal and opposite forces due to the acceleration. This is opposite to the G forces experienced by astronauts and fighter pilots as they accelerate in their aircraft. The researchers managed to show that it is indeed possible to split water in this environment. However, as water is split to create gas, bubbles form.
Earth-abundant first-row (3d) transition metal–based catalysts have been developed for the oxygen-evolution reaction (OER); however, they operate at overpotentials substantially above thermodynamic requirements. Density functional theory suggested that non-3d high-valency metals such as tungsten can modulate 3d metal oxides, providing near-optimal adsorption energies for OER intermediates. We developed a room-temperature synthesis to produce gelled oxyhydroxides materials with an atomically homogeneous metal distribution. These gelled FeCoW oxyhydroxides exhibit the lowest overpotential (191 millivolts) reported at 10 milliamperes per square centimeter in alkaline electrolyte. The catalyst shows no evidence of degradation after more than 500 hours of operation.
Ambitious plans to travel to Mars and some day form a colony on the red planet may have come a step closer to reality. Researchers from California Institute of Technology recently published research showing a way to turn water into oxygen and hydrogen in space. Both of these elements are essential for long-term space exploration, and could pave the way for future colonies, as well as allowing humans to venture further into the universe than ever before. In an article for The Conversation, Dr Charles Dunnill, senior lecturer in Energy at Swansea University, explains how important this discovery could be for human survival as we continue to outgrow our own planet. Space agencies and private companies already have advanced plans to send humans to Mars in the next few years – ultimately colonising it.