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Researchers develop free-standing nanowire mesh for direct solar water-splitting to produce H2; new design for “artificial leaf”
December 03, 2014
|The mesh with BiVO4 nanowire photoanode for water oxidation and Rh-SrTiO3 nanowire photocathode for water reduction produces hydrogen gas without an electron mediator. Credit: ACS, Liu et al. Click to enlarge.|
Researchers from UC Berkeley, Lawrence Berkeley National Laboratory and Nanyang Technological University, Singapore have developed a new technology for direct solar water-splitting—i.e., an “artificial leaf” to produce hydrogen—based on a nanowire mesh that lends itself to large-scale, low-cost production. A paper describing their work is published in the journal ACS Nano.
In the design, semiconductor photocatalysts are synthesized as one-dimensional nanowires, which are assembled into a free-standing, paper-like mesh using a vacuum filtration process from the paper industry. When immersed in water with visible light irradiation (λ ≥ 400 nm), the mesh produces hydrogen gas. Although boosting efficiency remains a challenge, their approach—unlike other artificial leaf systems—is free-standing and doesn’t require any additional wires or other external devices that would add to the environmental footprint.
Hydrogenation-assisted graphene origami nanocages exhibit leading hydrogen storage densities
March 17, 2014
Researchers from the University of Maryland have used molecular dynamics simulation to demonstrate graphene nano-cages which will open and close in response to an electric charge using a technique they call hydrogenation-assisted graphene origami (HAGO). The cages can stably store hydrogen molecules at a density of 9.7 wt % hydrogen—significantly above the US Department of Energy (DOE) target of 5.5 wt % by 2017 and 7.5 wt % by 2020.
The team has also demonstrated the potential to reach an even higher density and doing so is a future research goal. A paper on their work is published in the journal ACS Nano.