International Collaboration in Chemistry - Modular microtubular architectures for photo-driven water splitting

到2050年，世界目前的能源需求将翻一番，尽管这种增加的需求原则上可以通过化石燃料来满足（目前化石燃料占我们能源的70%以上），但二氧化碳排放量的增加无疑会带来有害的后果。另一种解决方案是利用来自太阳的丰富能源：每小时照射到地球表面的太阳能比人类目前每年使用的还要多。近年来，由于技术机构以及政府和商业部门认识到发展绿色、可持续能源的迫切需求和非凡机遇，对太阳能捕获的各个方面的研究都有了相当大的增长。基于效率、生产成本和使用寿命，光伏（PV）设备的竞争力日益增强。具体来说，最好的单晶硅基光伏器件的效率高达22%，但目前对于大规模使用来说过于昂贵。相比之下，染料敏化太阳能电池（DSSCs）的效率只有它的一半左右，但有可能以低得多的成本批量生产。然而，这些和其他发展中的光伏技术仅限于电能的产生和储存，虽然电池技术正在改进，但我们目前电池的能量密度（重量和摩尔能量密度）远远低于可用的燃料。这就是为什么目前许多活动的目标是利用阳光直接生产燃料。当然，地球上有一种已知的过程可以产生“太阳能燃料”——光合作用——尽管即使是这个过程，经过数十亿年的优化，对大多数陆生植物来说，效率也不到1%。因此，重要的是考虑利用太阳能生产燃料的所有可能途径。在这项工作中，我们将使用一系列新的分子金属氧化物，它们已经被证明是很有前途的催化剂，可以将水氧化和分解为氢和氧，因此有可能用于太阳能燃料的产生，通过与染料单元的直接结合，可以将太阳能转移到分子氧化物中。这将利用美国小组（用金属氧化物催化剂快速水氧化）和英国小组（当金属氧化物与染料阳离子结合时，微管状结构的生长）的最新发现。这意味着可以“生长”催化异质结构，在具有高表面积和坚固性的表面上将阳光转化为燃料，为“化石”自由能源解决方案开辟了一个全新的科学和应用领域。

The world's present energy requirements are set to double by 2050, and although this increased demand could, in principle, be met by fossil fuels (currently the source of over 70% of our energy), the increased CO2 output would undoubtedly have deleterious consequences.An alternative solution is to harness the abundant energy that comes from the sun: the amount of solar energy that strikes the surface of the earth each hour is more than mankind currently uses each year. Research on all aspects of solar energy capture has increased considerably in recent years because the technical establishments as well as government and business sectors realize both the pressing need and the extraordinary opportunity that exists in the development of green, sustainable sources of energy. Photovoltaic (PV) devices are increasingly competitive based on efficiency, production costs and operating lifetime. Specifically, the best single crystal Si-based PV devices are up to 22% efficient but are currently prohibitively expensive for large-scale use. In contrast, dye-sensitized solar cells (DSSCs) are only about half this efficient but have the potential to be produced in quantity at far lower cost. However, these and other developing PV technology is limited to generation and storage of electrical energy, and while battery technology is improving, the energy density (weight and molar energy density) in our current batteries is far lower than what is available in fuels. This is why much activity at present is aimed at the direct production of fuel using sunlight. There is, of course, one process already known on Earth that achieves production of "solar fuel" - photosynthesis - although even this process, optimized over billions of years, is less then 1% efficient for most terrestrial plants. It is important therefore to consider every possible route towards harnessing solar energy to produce fuels. In this work we will use a novel range of molecular metal oxides, which have already been shown to be promising catalysts for the oxidation and splitting of water in to hydrogen and oxygen and therefore potentially of use for the generation of solar fuels, by the direct combination with dye-units that can transfer the suns energy to molecular oxide. This will exploit the recent discoveries of the US group (very fast water oxidation with a metal oxide catalyst) and the UK group (growth of microscale tubular architectures when the metal oxide is combined with the dye-cation). This means it is possible to 'grow' catalytic heterostructures that could convert sunlight into fuels on surfaces in with high surface area and robustness opening up a whole new area of science and application to 'fossil' free energy solutions.