Thorne James E, Li Song, Du Chun, Qin Gaowu, Wang Dunwei
Department of Chemistry, Merkert Chemistry Center, Boston College , 2609 Beacon Street, Chestnut Hill, Massachusetts 02467, United States.
Key Lab for Anisotropy and Texture of Materials (MoE), Northeastern University , Shenyang 110819, China.
J Phys Chem Lett. 2015 Oct 15;6(20):4083-8. doi: 10.1021/acs.jpclett.5b01372. Epub 2015 Oct 1.
Photoelectrochemistry (PEC) holds potential as a direct route for solar energy storage. Its performance is governed by how efficiently photoexcited charges are separated and how fast the charges are transferred to the solution, both of which are highly sensitive to the photoelectrode surfaces near the electrolyte. While other aspects of a PEC system, such as the light-absorbing materials and the catalysts that facilitate charge transfer, have been extensively examined in the past, an underwhelming amount of attention has been paid to the energetics at the photoelectrode/electrolyte interface. The lack of understanding of this interface is an important reason why many photoelectrode materials fail to deliver the expected performance in harvesting solar energy in a PEC system. Using hematite (α-Fe2O3) as a material platform, we present in this Perspective how surface modifications can alter the energetics and the resulting consequences on the overall PEC performance. It has been shown that a detailed understanding of the photoelectrode/eletrolyte interfaces can contribute significantly to improving the performance of hematite, which enabled unassisted solar water splitting when combined with an amorphous Si photocathode.
光电化学（PEC）作为太阳能存储的直接途径具有潜力。其性能取决于光激发电荷的分离效率以及电荷转移到溶液中的速度，而这两者对靠近电解质的光电极表面都高度敏感。虽然过去已经广泛研究了PEC系统的其他方面，如光吸收材料和促进电荷转移的催化剂，但对光电极/电解质界面的能量学关注不足。对该界面缺乏了解是许多光电极材料在PEC系统中未能实现预期太阳能收集性能的一个重要原因。以赤铁矿（α-Fe2O3）为材料平台，我们在本观点文章中展示了表面修饰如何改变能量学以及对整体PEC性能产生的影响。已经表明，对光电极/电解质界面的详细了解可以显著有助于提高赤铁矿的性能，当与非晶硅光阴极结合时，赤铁矿能够实现无辅助太阳能水分解。
