Interface Engineering for Solar Fuels

化石燃料的使用和由此产生的二氧化碳排放正在加剧全球气候变化。氢气的替代用途可以减少二氧化碳排放，改善城市地区的空气质量，因为燃烧氢气会产生无害的水。为了实现这一潜力，我们需要找到生产氢燃料的清洁方法。水分解成氢（和氧）可以通过使用可再生能源（如太阳能、风能或水力发电）发电的电解槽清洁地实现。一种更直接的方法是，利用光电化学（PEC）电池的光电电极中集成的阳光和半导体吸收层，水也可以被干净地分解。PEC太阳能水分解受限于光诱导电荷寿命差和半导体表面在电解质界面处分解水的催化性能差。该奖学金旨在开发新的方法来设计半导体和电解质之间的界面，以优化半导体的性能并实现高效的太阳能设备。我们将开发制造方法来调整这些界面并提高其PEC最终性能。光电极将被制备成定向的，带有暴露的活性晶体面，或者在其表面上有额外的层来中和水电解质。系统的方法包括新的合成、先进的电化学表征和太阳能水分解性能测试，以确定形成光电极的最佳条件和使其性能更好的特性。最后，最好的光电极将集成在串联电池中，以提高太阳能水分解的效率。具有工程界面的半导体材料的制备将对光电化学、光催化、光电等领域的研究及其能源应用产生重大影响。这将确保为当代和后代实现更可持续的清洁能源组合取得重要进展。

The use of fossil fuels and resulting CO2 emissions are exacerbating global climate change. The alternative use of hydrogen could cut CO2 emissions and improve air quality of urban areas, since burning hydrogen generates harmless water. To realise this potential we need to find clean ways to produce hydrogen fuel. Water splitting into hydrogen (and oxygen) can be achieved cleanly with electrolysers running on electricity from renewable sources such as solar, wind or hydropower. In a more direct manner, water can also be cleanly split using sunlight and semiconductor absorbing layers integrated in photoelectrodes of photoelectrochemical (PEC) cells. PEC solar water splitting is limited by both poor lifetime of photo-induced charges and poor catalytic properties of semiconductor surfaces to split water at the electrolyte interface.This fellowship aims to develop novel approaches to engineer the interface between semiconductors and electrolytes, in order to optimise the performance of the semiconductors and achieve efficient solar energy devices. We will develop fabrication methods to tune those interfaces and boost their PEC final performance. Photoelectrodes will be prepared oriented and with exposed active crystal facets, or with extra layers on their surface to mediate with aqueous electrolytes. A systematic approach involving novel syntheses, advanced electrochemical characterisation and solar water splitting performance tests will be carried out to establish the optimal conditions for the formation of photoelectrodes and the characteristics which make them better performing. Finally, best photoelectrodes will be integrated in tandem cells for more efficient solar water splitting.Preparing semiconductors with engineered interface will have a considerable impact on the research of (photo)electrochemistry, photocatalysis, photovoltaics and on their energy application. This will ensure important advances towards a more sustainable energy mix of clean energy for current and future generations.