Li Xiaopeng, Xiao Yanjun, Zhou Keya, Wang Junna, Schweizer Stefan L, Sprafke Alexander, Lee Jung-Ho, Wehrspohn Ralf B
Max-Planck Institute of Microstructure Physics, Weinberg 2, Halle D-06120, Germany.
Phys Chem Chem Phys. 2015 Jan 14;17(2):800-4. doi: 10.1039/c4cp04396k. Epub 2014 Nov 18.
The origin of the photocurrent enhancement and the overpotential reduction in solar water splitting employing nanostructured silicon is still a matter of debate. A set of tapered Si nanowires (SiNWs) has been designed for clarifying the impact of nanostructured Si on the hydrogen evolution reaction (HER) while precisely tailoring several interference factors such as surface area, light absorption and surface defect density. We find that defect passivation by KOH achieved by tapering is much more beneficial than the optical gain. Surfactant-mediated modification of SiNWs is capable of engineering the band structure. As a result, we suggest a guideline for nanostructured Si photoelectrodes optimized for the HER.
在采用纳米结构硅的太阳能水分解中，光电流增强和过电位降低的起源仍是一个有争议的问题。设计了一组锥形硅纳米线（SiNWs），以阐明纳米结构硅对析氢反应（HER）的影响，同时精确调整诸如表面积、光吸收和表面缺陷密度等几个干扰因素。我们发现，通过锥形化实现的KOH对缺陷的钝化比光学增益更有益。表面活性剂介导的SiNWs修饰能够设计能带结构。因此，我们提出了针对析氢反应优化的纳米结构硅光电极的指导方针。
