Over billions of years, plants have been developing perhaps the most efficient power supply through photosynthesis. Don’t you think they are smarter than us?? As all know, Photosynthesises process of the converting of sunlight, carbon dioxide and water into usable fuel and emitting useful oxygen in the form of carbohydrates, or sugars by green plants. Their trick of harvesting sunlight was always a mystery to scientists…
Scientists are now very much closer to mimic photosynthesis to perfection which will allow to development of safer, cleaner renewable energy sources…Yes “Artificial photosynthesis is the leading candidate”. It is the industrial process of preparing fuels and chemicals from nothing more than carbon dioxide, water and sunlight. It is a vital process that would be the foundation of a world that would no longer need fossil fuels. More and more experiments are going on every day on this topic.
Scientists from Harvard University’s Faculty of Arts and Sciences, Harvard Medical School and the Wyss Institute for Biologically Inspired Engineering have created a “bionic leaf” that uses bacteria to convert solar energy into a liquid fuel. Artificial leaf uses a catalyst to make sunlight split water into hydrogen and oxygen, with a bacterium engineered to convert carbon dioxide plus hydrogen into the liquid fuel isopropanol. This study tells us how an artificial leaf could be used with a special bacterium to produce a liquid “solar fuel.”
Recently scientists from the California Institute of Technology (Caltech) have come up with solar electrolyzer to make liquid fuel. They have developed an electrically conductive film that could help pave the way for devices capable of harnessing sunlight to split water into hydrogen fuel. The hydrogen produced could be stored and used to generate electricity at night in power plants or fuel cell vehicles. They used two commercially proven technologies to create their device- electrolysis and silicon or cadmium-telluride solar cells. This process requires two light-sensitive electrodes: One oxidizes water molecules to form oxygen gas, protons and electrons, while the other electrode combines protons and electrons to generate hydrogen gas and a membrane which acts as a barrier separating the two electrodes so the gas can enter a pipeline without exploding. The team observed that nickel oxide film effectively separated the electrodes.
Researchers have built the electrodes out of common semiconductors such as silicon or gallium arsenide which absorb light and are also used in solar panels. But a major problem is that these materials develop an oxide layer (that is, rust) when exposed to water. They have experimented with creating protective coatings for the electrodes, but all previous attempts have failed for various reasons. In the new system, researchers added catalysts to solar cells, allowing them to double as electrolyzer electrodes and also optimized the catalysts to work with the solar cells. The nickel oxide used can serve as a catalyst and also protect solar cells. The catalyst helps free oxygen atoms from water molecules and produces oxygen gas, using energy from the solar cells.
According to researchers, the film coating allows a major process in the artificial photosynthesis to be conducted at topmost effectiveness, stability and efficiency. It also prevents the dangerous mixing of oxygen and hydrogen. This development could help lead to safe, efficient artificial photosynthetic systems called solar-fuel generators or “artificial leaves” that replicate the natural process of photosynthesis.
I think these laboratory methods will overcome the major limitations that inhibit the energy production when sun is not shining or wind is not blowing. I.e. no electricity is being harvested and stored in batteries which mean only a certain amount of energy can be collected and you are on battery power and experience a loss of efficiency. Nature still has much to teach us, observing carefully we can modify ourselves and surroundings. This may be one of the important steps towards the design of novel artificial energy transduction systems to produce renewable fuels which will be sufficiently cheap to compete with carbon-based fuels.