My Blog. Water and sunlight. Windows generate electricity - 1/12. Oxford Photovoltaics has been spun out of the University of Oxford to develop solar cell windows. From the Clarendon lab, its fundamental technology is a screen-printable solid-state dye-sensitised solar cell (DSSC). DSSCs, also known as Grätzel cells after their inventor, owe more to photosynthesis than to conventional silicon solar cells.
In them, a dye and titanium dioxide are combined with an electrolyte. The dye absorbs photons, causing electrons to be transferred to the titanium dioxide, from where they can leave the cell. “Regular DSSCs use a liquid electrolyte. We screen print the cell and the constituents set as a solid,” CEO Kevin Arthur told Electronics Weekly. As such, the Oxford DSSC can be printed onto glass with no fear of it drying out. “One of the great advantages is that we can process it over large areas very easily,” said the technology developer Dr Henry Snaith.
No one is going to want to replace the windows of a building because its solar cells have expired. Fukuzumi’s Group. New Energy and Fuel. May The Berkley Lab at the University of California Berkley has come up with a new catalyst for splitting water. In fairness to readers, there have been other claims from out there that didn’t seem, well, practical. So they’ve been overlooked. But this time the sense of the work seems to make some sense. The oxygen gas it seems, isn’t fully coming off with the hydrogen, this is new. The molybdenum-oxo complex the Berkley Lab team discovered is a high valence metal with the chemical name of (PY5Me2)Mo-oxo. Berkley Lab New Water Catalyst. What’s different is the new catalyst is “consumed,” or more accurately, reformed as it’s used picking up some of the oxygen. The Berkley team’s catalyst is cheap, or not so expensive as a conventional electrolysis kit. The ability to use untreated or unconditioned water would save investment and operating expense, narrowing the main operations to handling the hydrogen and recycling the catalyst.
Ultracapacitors to Boost the Range of Electric Cars. A startup called Nanotune says its ultracapacitor technology could make electric cars cheaper and extend their range. The company, based in Mountain View, California, has developed a way to make electrodes that results in ultracapacitors with five to seven times as much storage capacity as conventional ones. Conventional ultracapacitors, which have the advantage of delivering fast bursts of power and can be recharged hundreds of thousands of times without losing much capacity, are too expensive and store too little energy to replace batteries. Nanotune, however, which has raised $3 million from the venture capital firm Draper Fisher Jurvetson, says its ultracapacitors are close to competing with batteries in terms of energy storage, and could soon surpass them. Using a conventional electrolyte, the company has demonstrated energy storage of 20 watt-hours per kilogram, as opposed to roughly five watt-hours for a conventional ultracapacitor.
Water Catalyst by Light. Titre du document / Document title Auteur(s) / Author(s) Résumé / Abstract Discovery of an efficient catalyst bearing low overpotential toward water oxidation is a key step for light-driven water splitting into dioxygen and dihydrogen. A mononuclear ruthenium complex, Ru(II)L(pic)2 (1) (H2L = 2,2'-bipyridine-6,6'-dicarboxylic acid; pic = 4-picoline), was found capable of oxidizing water eletrochemically at a relatively low potential and promoting light-driven water oxidation using a three-component system composed of a photosensitizer, sacrificial electron acceptor, and complex 1. Revue / Journal Title Source / Source 2010, vol. 49, no1, pp. 209-215 [7 page(s) (article)] Langue / Language Anglais Editeur / Publisher American Chemical Society, Washington, DC, ETATS-UNIS (1962) (Revue) Localisation / Location. Splitting Water with Ruthenium. Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, and Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000 J.
Am. Chem. Soc., 2010, 132 (5), pp 1545–1557 DOI: 10.1021/ja904906v Publication Date (Web): January 19, 2010 Copyright © 2010 American Chemical Society Section: Abstract The mechanism of Ce(IV) water oxidation catalyzed by [Ru(tpy)(bpm)(OH2)]2+ (tpy = 2,2′:6′,2′′-terpyridine; bpm = 2,2′-bipyrimidine) and related single-site catalysts has been determined by a combination of mixing and stopped-flow experiments with spectrophotometric monitoring. Citing Articles View all 151 citing articles Citation data is made available by participants in CrossRef's Cited-by Linking service. This article has been cited by 63 ACS Journal articles (5 most recent appear below). Effect of Substituents on the Water Oxidation Activity of [RuII(terpy)(phen)Cl]+ ProcatalystsDakshika C. Water-splitting catalyst. (PhysOrg.com) -- Expanding on work published two years ago, MIT's Daniel Nocera and his associates have found yet another formulation, based on inexpensive and widely available materials, that can efficiently catalyze the splitting of water molecules using electricity.
This could ultimately form the basis for new storage systems that would allow buildings to be completely independent and self-sustaining in terms of energy: The systems would use energy from intermittent sources like sunlight or wind to create hydrogen fuel, which could then be used in fuel cells or other devices to produce electricity or transportation fuels as needed. Nocera, the Henry Dreyfus Professor of Energy and Professor of Chemistry, says that solar energy is the only feasible long-term way of meeting the world’s ever-increasing needs for energy, and that storage technology will be the key enabling factor to make sunlight practical as a dominant source of energy. But the research is still in an early stage. The Mechanism of Water Oxidation.
Daniel Nocera's work. Water Oxidation Catalyst. MIT's artificial leaf is ten times more efficient than the real thing. Speaking at the National Meeting of the American Chemical Society in California, MIT professor Daniel Nocera claims to have created an artificial leaf, made from stable and inexpensive materials, which mimics nature's photosynthesis process. The device is an advanced solar cell, no bigger than a typical playing card, which is left floating in a pool of water. Then, much like a natural leaf, it uses sunlight to split the water into its two core components, oxygen and hydrogen, which are stored in a fuel cell to be used when producing electricity.
Nocera's leaf is stable -- operating continuously for at least 45 hours without a drop in activity in preliminary tests -- and made of widely available, inexpensive materials -- like silicon, electronics and chemical catalysts. It's also powerful, as much as ten times more efficient at carrying out photosynthesis than a natural leaf. Those are impressive claims, but they're also not just pie-in-the-sky, conceptual thoughts. Nanocapsules for photosynthesis. Storable solar energy.
MIT scientists are developing an alternative to photovoltaic and solar-thermal systems for capturing the sun's energy. Discovered decades ago, but largely undeveloped, the thermo-chemical approach captures solar energy in the configuration of certain molecules which can then release it on demand to produce usable heat. Unlike conventional solar-thermal systems, which even with effective insulation let the heat gradually leak away, the heat-storing chemicals can remain stable for years. But researchers couldn't could find a chemical that could reliably and reversibly switch between two states, absorbing sunlight to go into one state and then releasing heat when it reverted to the first state.
One such compound was discovered in 1996, but it included ruthenium, a rare and expensive element - and nobody understood how it worked, making it harder to find a cheaper variant. However, it turns out there’s an intermediate step that plays a major role, says Jeffrey Grossman. Synthetic Rubisco. For 91 years, Nenana, a village of 450 people, 55 miles southwest of Fairbanks, has held a wager on the exact moment that the ice breaks up on the nearby Tanana River. The winners in 2007 shared a jackpot of $303,272. But for geophysicists, the historical record of Tanana's yearly thaw since 1917 is far more valuable as evidence of a longterm warming trend affecting lakes and rivers throughout the Northern Hemisphere.
For example, researchers at the University of Wisconsin's Center for Limnology who analyzed newspaper archives, transport ledgers and religious records dating back to the 16th century found 17 lakes in Europe, Asia and the US with records going back 150 years. And, on average, these lakes are thawing about 13 days earlier now than when first recorded. The Tanana records bolster this "global warming" hypothesis by showing that spring in central Alaska is some 10 days earlier today than in 1960. Greenhouse gas es, such as carbon dioxide and methane ," says the .