As for graphene, we can certainly expect it to be catalytically and chemically active in other reactions, not only those involving hydrogen. Lead author of the paper, Professor Geim, added: “As nanorippling naturally occurs in all atomically thin crystals, because of thermal fluctuations and unavoidable local mechanical strain, other 2D materials may also show similarly enhanced reactivity. We have also proved that nanoscale corrugations are more important for catalysis than the ‘usual suspects’ such as vacancies, edges, and other defects on graphene’s surface,” said Dr Pengzhan Sun, first author of the paper. “Our paper shows that freestanding graphene is quite different from both graphite and atomically flat graphene that are chemically extremely inert. The results have implications for the use of other 2D materials as catalysts However, graphene was only required in tiny quantities, less than 100 times the latter catalysts. The analysis of the gas showed that the amount of HD generated by monolayer graphene was around the same as for the known hydrogen catalysts, such as zirconia, magnesium oxide, and copper. This greatly contrasted with the behaviour of graphite and other carbon-based materials under the same conditions. They discovered that graphene does behave as a powerful catalyst, converting H2 and D2 into HD. The team evaluated whether this reactivity is enough to make the material an efficient catalyst, by using a mixture of hydrogen and deuterium gases (D2). It was also found that the activation energy for its dissociation into atomic hydrogen (H) was relatively small. They demonstrated that graphene’s nanoscale corrugations were linked to its chemical reactivity with molecular hydrogen (H2) by using ultrasensitive gas flow measurements and Raman spectroscopy. In collaboration with researchers from China and the US, the team from the National Graphene Institute conducted a series of experiments to show that the non-flatness of graphene makes it a strong catalyst. The non-flatness of graphene makes it a strong catalyst The work, ‘ Unexpected catalytic activity of nanorippled graphene ,’ is published in the Proceedings of the National Academy of Sciences (PNAS). The effect is likely to be present in all two-dimensional materials, which inherently are all non-flat. The findings were unexpected, with previous research predicting that graphene would be as chemically inert as the bulk graphite from which it is obtained. Led by Professor Andre Geim from the National Graphene Institute (NGI), the researchers found that nanorippled graphene can accelerate hydrogen splitting as well as the best metallic-based catalysts. A team of researchers has found that nanoripples in graphene can make it a strong catalyst, contrary to predictions that the carbon sheet is as chemically inert as bulk graphite.
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