親子觀星會

https://buzzorange.com/techorange/2020/06/10/new-catalyst-can-nearly-100-transfer-solar-power/?fbclid=IwAR30TYfUgxI3JyT6aJ5hfBOO2qmKQWSshY23N2526XB4piArrTt9TDxpX9E

日本科學家也用到了鋁，但 鋁是作為催化劑的一種成分，而非反應物，可以反複使用 。
高效率光解水催化劑有這「四大關鍵」

研究表明，如果太陽光催化分解水的效率達到 10%，就能具備經濟上的競爭力。

但是，光催化半導體的轉換效率通常遠低於 10%。這是因為光催化過程非常複雜，並且要求半導體顆粒具有多種特性的組合。

要實現高效率地光解水，催化劑需要做到以下幾步：

    吸收光
    產生並分離電子—空穴對
    使空穴和電子傳播到催化劑與水的交界面
    從水中催化產生氫和氧


量子效率 96%

不是轉換率

==

https://www.nature.com/articles/s41586-020-2278-9


    Article
    Published: 27 May 2020

Photocatalytic water splitting with a quantum efficiency of almost unity

Overall water splitting, evolving hydrogen and oxygen in a 2:1 stoichiometric ratio,  using particulate photocatalysts is a potential means of achieving scalable and economically viable solar hydrogen production. To obtain high solar energy conversion efficiency, the quantum efficiency of the photocatalytic reaction must be increased over a wide range of wavelengths and semiconductors with narrow bandgaps need to be designed. However, the quantum efficiency associated with overall water splitting using existing photocatalysts is typically lower than ten per cent1,2. Thus, whether a particulate photocatalyst can enable a quantum efficiency of 100 per cent for the greatly endergonic water-splitting reaction remains an open question. Here we demonstrate overall water splitting at an external quantum efficiency of up to 96 per cent at wavelengths between 350 and 360 nanometres, which is equivalent to an internal quantum efficiency of almost unity, using a modified aluminium-doped strontium titanate (SrTiO3:Al) photocatalyst3,4. By selectively photodepositing the cocatalysts Rh/Cr2O3 (ref. 5) and CoOOH (refs. 3,6) for the hydrogen and oxygen evolution reactions, respectively, on different crystal facets of the semiconductor particles using anisotropic charge transport, the hydrogen and oxygen evolution reactions could be promoted separately. This enabled multiple consecutive forward charge transfers without backward charge transfer, reaching the upper limit of quantum efficiency for overall water splitting. Our work demonstrates the feasibility of overall water splitting free from charge recombination losses and introduces an ideal cocatalyst/photocatalyst structure for efficient water splitting.