Nanoscale carbon, for example, is enabling greater efficiency and longer lifetimes for the familiar activated carbon water filter.

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Leiba says that activated carbon water filters -- like Brita pitchers or faucet attachments -- are a safe and affordable option for filtering tap water.

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The company is also experimenting with a new way of storing the hydrogen that will fuel its cells a fabric made of fibres of activated carbon that can (when cooled with liquid nitrogen) soak up the same amount of energy per kilogram as petrol.

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The architects worked with Pureti, a green-tech manufacturer (and winner of a 2011 "What's New" award from Popular Science), to develop a spray version of a titanium nano particle that, when activated by sunlight, oxidizes airborne particulates and converts them into water vapor and trace amounts of carbon dioxide.

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And although activated charcoal is not at all efficient in chemically trapping (or adsorbing) methane, it will readily grab onto carbon dioxide and other pollutants.

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