Materials for Energy Conversion and Storage (MECS), Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands.
Center for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands.
Nat Commun. 2017 Jun 29;8:15968. doi: 10.1038/ncomms15968.
Solar-assisted water splitting can potentially provide an efficient route for large-scale renewable energy conversion and storage. It is essential for such a system to provide a sufficiently high photocurrent and photovoltage to drive the water oxidation reaction. Here we demonstrate a photoanode that is capable of achieving a high photovoltage by engineering the interfacial energetics of metal-insulator-semiconductor junctions. We evaluate the importance of using two metals to decouple the functionalities for a Schottky contact and a highly efficient catalyst. We also illustrate the improvement of the photovoltage upon incidental oxidation of the metallic surface layer in KOH solution. Additionally, we analyse the role of the thin insulating layer to the pinning and depinning of Fermi level that is responsible to the resulting photovoltage. Finally, we report the advantage of using dual metal overlayers as a simple protection route for highly efficient metal-insulator-semiconductor photoanodes by showing over 200 h of operational stability.
太阳能辅助水分解有可能为大规模可再生能源的转化和存储提供一条有效的途径。对于这样一个系统来说，提供足够高的光电流和光电压来驱动水氧化反应是至关重要的。在这里，我们通过对金属-绝缘体-半导体结的界面能态工程，展示了一种能够实现高光电压的光阳极。我们评估了使用两种金属来分离肖特基接触和高效催化剂的功能的重要性。我们还说明了在 KOH 溶液中金属表面层偶然氧化时光电压的提高。此外，我们分析了薄绝缘层对费米能级钉扎和解钉扎的作用，这是导致光电压的原因。最后，我们通过展示超过 200 小时的工作稳定性，报告了使用双金属覆盖层作为高效金属-绝缘体-半导体光阳极的简单保护途径的优势。
