scholarly journals Solar-driven water-splitting provides a solution to the energy problem underpinning climate change

2020 ◽  
Vol 48 (6) ◽  
pp. 2865-2874
Author(s):  
James Barber
Keyword(s):  
Water Splitting ◽  
Fossil Fuels ◽  
Organic Molecules ◽  
Big Bang ◽  
Oxygenic Photosynthesis ◽  
X Ray Diffraction ◽  
Significant Step ◽  
Oxygen Evolving ◽  
The Big Bang ◽  
Sun Light

The emergence of the oxygen-evolving photosystem two complex over 2.6 billion years ago represented the ‘big bang of evolution’ on planet Earth. It allowed phototrophic organisms to use sun light as an energy source to extract electrons and protons from water, and concomitantly release oxygen. Oxygenic photosynthesis not only created an aerobic atmosphere but also removed CO2 to produce the organic molecules that make up the current global biomass and fossil fuel. In addition, it paved the way for animal life. Today extensive burning of fossil fuels is reversing the results of photosynthesis through billions of years, rapidly releasing CO2 back into the atmosphere and consequently increasing the temperature of the planet. There is an urgent need to develop new sustainable energy sources, but the choice is not obvious. My approach to this problem has been to unravel the blueprint of photosystem II (PSII) and to develop an ‘Artificial Leaf’ technology. A significant step with respect to that mission was achieved at Imperial College when we could conclude from X-ray diffraction of PSII crystals, that the water-splitting catalytic centre consists of a unique Mn3Ca2+O4 cubane structure with a fourth dangler Mn oxo-bonded to the cubane. Here I use this and more recent structures to discuss the mechanism of water splitting and O–O bond formation. Furthermore, I will address how this information can be used to design novel water-splitting catalysts and highlight recent progress in this direction. My conviction is ‘if plants can do it, we can do it — after all it is all about chemistry’.

Synthesis of CaMn2O4-related electrocatalyst for oxygen evolution electrode of water-splitting

2014 ◽  
Vol 1640 ◽  
Author(s):  
Yuya Taki ◽  
Zhenquan Tan ◽  
Satoshi Ohara ◽  
Takashi Itoh ◽  
Yoshiaki Nakano ◽  
...  
Keyword(s):  
Solar Cells ◽  
Electric Power ◽  
Water Splitting ◽  
Oxygen Evolution ◽  
Electrocatalytic Activity ◽  
Fossil Fuels ◽  
Weight Ratio ◽  
Synthesis Condition ◽  
Carbon Paste ◽  
Oxygen Evolving

ABSTRACTWater-splitting by using electric power produced by solar cells is promising system to produce hydrogen without fossil fuels. Oxygen evolving catalyst is, however, major problem to prevent using this system widely because precious materials are used in the catalyst. Considering from the photosynthesis II of plants, the compound of Ca-Mn-O is one of the candidates for the oxygen evolving catalyst. In this study, the synthesis condition and the oxygen evolving electrocatalytic activity of CaMn2O4•xH2O are investigated. The overpotential at 0.1 mA/cm2 was 0.28 V when using the electrode of carbon paste and CaMn2O4•H2O with the weight ratio of 3:1.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

A view of the universe before the big bang

2006 ◽  
Vol 190 ◽  
pp. 15-15
Author(s):  
D CASTELVECCHI
Keyword(s):  
Big Bang ◽  
The Big Bang ◽  
The Universe

The First Galaxies in the Universe

2013 ◽  
Author(s):  
Abraham Loeb ◽  
Steven R. Furlanetto
Keyword(s):  
Galaxy Evolution ◽  
Big Bang ◽  
First Stars ◽  
Distant Galaxies ◽  
Formation And Evolution ◽  
Early Galaxies ◽  
First Galaxies ◽  
Large Telescopes ◽  
New Generation ◽  
The Big Bang

This book provides a comprehensive, self-contained introduction to one of the most exciting frontiers in astrophysics today: the quest to understand how the oldest and most distant galaxies in our universe first formed. Until now, most research on this question has been theoretical, but the next few years will bring about a new generation of large telescopes that promise to supply a flood of data about the infant universe during its first billion years after the big bang. This book bridges the gap between theory and observation. It is an invaluable reference for students and researchers on early galaxies. The book starts from basic physical principles before moving on to more advanced material. Topics include the gravitational growth of structure, the intergalactic medium, the formation and evolution of the first stars and black holes, feedback and galaxy evolution, reionization, 21-cm cosmology, and more.

The Planet in a Pebble

2010 ◽  
Author(s):  
Jan Zalasiewicz
Keyword(s):  
Solar System ◽  
Volcanic Eruptions ◽  
Big Bang ◽  
Forensic Analysis ◽  
Mineral Matter ◽  
Supernova Explosions ◽  
Deep Underground ◽  
The Big Bang ◽  
The Universe

This is the story of a single pebble. It is just a normal pebble, as you might pick up on holiday - on a beach in Wales, say. Its history, though, carries us into abyssal depths of time, and across the farthest reaches of space. This is a narrative of the Earth's long and dramatic history, as gleaned from a single pebble. It begins as the pebble-particles form amid unimaginable violence in distal realms of the Universe, in the Big Bang and in supernova explosions and continues amid the construction of the Solar System. Jan Zalasiewicz shows the almost incredible complexity present in such a small and apparently mundane object. Many events in the Earth's ancient past can be deciphered from a pebble: volcanic eruptions; the lives and deaths of extinct animals and plants; the alien nature of long-vanished oceans; and transformations deep underground, including the creations of fool's gold and of oil. Zalasiewicz demonstrates how geologists reach deep into the Earth's past by forensic analysis of even the tiniest amounts of mineral matter. Many stories are crammed into each and every pebble around us. It may be small, and ordinary, this pebble - but it is also an eloquent part of our Earth's extraordinary, never-ending story.

When did the Big Bang happen?

1996 ◽  
Vol 10 (1) ◽  
pp. 33-33
Author(s):  
F. A. Tsitsin
Keyword(s):  
Big Bang ◽  
The Big Bang
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