Many scientists are turning to mimicking nature to probe its secrets, but Daniel Nocera, the Patterson Rockwood Professor of Energy at Harvard University, has gone far beyond his natural model. Reported in 2012, Nocera came up with the idea of an “artificial leaf,” a silicon sheet with a layer of cobalt-based catalyst that releases oxygen on one side and a layer a nickel-molybdenum-zinc alloy on the other side that releases hydrogen. Several researchers have followed this initial breakthrough, trying different materials and combinations of ingredients. For a while, it looked as though Nocera turned his attention to battery development, but recent news shows he’s back investigating artificial leaves – with great improvements over his initial efforts – and those of nature, it would seem. His newest approach combines the catalytic energy of the original leaf with a bacterium that makes useful fluids out of the hydrogen generated. It makes the leaf’s output a practical liquid – a fuel. It probably …