[kitchencabinetforum] STANFORD FINDS THE HOLY GRAIL OF CLEAN ENERGY!

The process of splitting water into pure oxygen and clean-burning hydrogen fuel has long been the Holy Grail for clean-energy advocates as a method of large-scale energy storage, but the idea faces technical challenges. Stanford researchers have solved one of the most important ones. http://venitism.blogspot.com

Solar energy is fine when the sun is shining. But what about at night or when it is cloudy? To be truly useful, sunshine must be converted to a form of energy that can be stored for use when the sun is hiding.

The notion of using sunshine to split water into oxygen and storable hydrogen fuel has been championed by clean-energy advocates for decades, but stubborn challenges have prevented adoption of an otherwise promising technology.

A team of Stanford researchers have solved one of the most vexing scientific details blocking us from such a clean-energy future. The team, led by materials science engineer Paul McIntyre and chemist Christopher Chidsey, has devised a robust silicon-based solar electrode that shows remarkable endurance in the highly corrosive environment inherent in the process of splitting water.

Conceptually, splitting water could not be simpler. Scientists have long known that applying a voltage across two electrodes submerged in water splits the water molecules into their component elements, oxygen and hydrogen. http://venitism.blogspot.com

From an environmental standpoint, the process is a dream: an electrochemical reaction whose only requirements are water and electricity and whose only byproducts are pure oxygen and hydrogen, a clean-burning fuel applicable in a promising new class of renewable energy applications. In fact, hydrogen is the cleanest burning chemical fuel known.

"In theory, water splitting is a clean and efficient energy storage mechanism. Unfortunately, solving one problem creates another," said McIntyre, associate professor of materials science and engineering. "The most abundant solar electrodes we have today are made of silicon, a material that corrodes and fails almost immediately when exposed to oxygen, one of the byproducts of the reaction."

This particular problem has vexed researchers since at least the 1970s. Many had given up, but McIntyre and Chidsey have devised a clever solution. They coated their silicon electrodes with a protective, ultra-thin layer of titanium dioxide.

"Titanium dioxide is perfect for this application," explained McIntyre. "It is both transparent to light and it can be efficient for transferring electricity, all while protecting the silicon from corrosion."

Sunlight travels through the protective titanium dioxide into the photosensitive silicon, which produces a flow of electrons that travels through the electrochemical cell into the water, splitting the hydrogen from the oxygen. The hydrogen gas can be stored and then, when the sun is not shining, the process can be reversed, reuniting hydrogen and oxygen back into water to produce electricity.
http://venitism.blogspot.com