MIT chemistry professor Daniel Nocera led research on the artificial leaf project, says he and his colleagues took their cues from plants, which are literally buzzing with electricity.
“What happens is that sunlight comes in and hits the leaf and then the leaf immediately takes that sunlight and makes a wireless current,”says Nocera.
During photosynthesis, the energy in sunlight splits water molecules into hydrogen and oxygen. The hydrogen joins with carbon dioxide to make sugar, an essential fuel for plant growth. In Nocera’s laboratory, scientists replicated that chemical process using a silicon device about the size and shape of a playing card, only thinner. It's coated with nickel and cobalt catalysts that when exposed to water and ultraviolet light, accelerate a chemical reaction.
“So you can literally just take this bottle of water and we could take the chip, put the chip inside the bottle of water, and go holding it up in the sun and you would start seeing hydrogen and oxygen bubbles coming up.”
The hydrogen is then recombined with the oxygen in a fuel cell to produce electricity. Nocera’s work builds on previous research. John Turner of the National Renewable Energy Laboratory pioneered the concept in 1998 using materials too expensive and unstable for commercialization.
Nocera says his so-called practical artificial leaf uses less expensive materials, is more stable and more efficient than that earlier design. He says the challenge is to collect the gases coming off the silicon and store them until the energy is needed. “That has to be engineered still,” he adds. “We don't know how to do that. It will be something that we will start doing pretty soon. You’ll be storing a fair amount of energy because this system is working at the efficiency more or less of the solar cell.”
In laboratory experiments, Nocera's solar cell prototype operated continuously for 45 hours without a drop in electrical output. Nocera notes that it works in any type of water. “So you can use natural water sources, which for us is a big deal, because if you are in rural parts of the world. especially where they are poor, it is really costly to bring in pure water and so, the fact that you can go over there' to a puddle and pick the water up and begin using it, is something that is very powerful for us."
Nocera believes the artificial leaf could be especially useful as an inexpensive source of electricity for low-income populations in developing countries. The goal, Nocera says, is to make each home its own power station. He predicts a commercial version of the artificial leaf will be on the market within three years.
【小题1】MIT chemistry professor Daniel Norcera's research is different from John Turner's mainly in that________.| A．Norcera's research outcome is too commercialized |
| B．Norcera has found a cheaper and steadier material |
| C．Norcera's working system is like the solar cell |
| D．Norcera's research is original and unprecedented |
| A．an efficient way of storing gases coming off the silicon |
| B．a feasible system that is as efficient as solar cell |
| C．a silicon device that can accelerate the chemical reaction |
| D．how to spread the cheap source of electricity in developing countries |
| A．It is convenient for every home to own a power station |
| B．It can change the ordinary water into pure water |
| C．It has a commercial value for poor populations |
| D．It can recycle waste water and thus eco-friendly |
| A．Plants Can Produce Cheap and Steady Electricity |
| B．Storage of Energy Is a Tough Challenge |
| C．Artificial Leaf Tuns Sunlight into Electric Power |
| D．Inexpensive Source of Electricity Is Finally Available |
