Maximizing Solar Water Splitting Performance by Nanoscopic Control of the Charge Carrier Fluxes across Semiconductor–Electrocatalyst Junctions
Maximizing Solar Water Splitting Performance by Nanoscopic Control of the Charge Carrier Fluxes across Semiconductor–Electrocatalyst Junctions
复制标题
DOI：
10.1021/acscatal.8b01929
复制
发表时间：
2018-08
期刊：
影响因子：
12.9
通讯作者：
Joseph Quinn;J. Hemmerling;S. Linic
中科院分区：
文献类型：
--
作者：
Joseph Quinn;J. Hemmerling;S. Linic
半导体和电催化剂之间的保护绝缘层使得原本不稳定的半导体能够用于光催化水分解。通常认为，在这些系统中，金属电催化剂必须具有功函数性质，该功函数性质在半导体和电催化剂之间设置高的固有势垒高度，并且绝缘层应该尽可能薄。在这项研究中，我们表明，对于固有的低势垒高度的系统，光电压可以显着提高通过调整绝缘层的厚度。我们证明了这一点的情况下，由n型硅，氧化铪保护层（厚度0-3纳米），和镍电催化剂组成的系统的研究。通过优化保护层的厚度，我们观察到增加的效率，光催化析氧与厚Ni电催化剂上的n-Si。我们的研究结果为使用具有良好电催化性能的廉价电催化剂开辟了途径。
Protective insulating layers between a semiconductor and an electrocatalyst enable otherwise unstable semiconductors to be used in photocatalytic water splitting. It is generally argued that in these systems the metal electrocatalyst must have work function properties that set a high inherent barrier height between the semiconductor and electrocatalyst and that the insulating layer should be as thin as possible. In this study we show that, for systems which suffer from inherently low barrier heights, the photovoltage can be significantly improved by tuning the thickness of the insulating layer. We demonstrate this in a case study of a system consisting of n-type silicon, a hafnium oxide protective layer (thickness 0–3 nm), and a Ni electrocatalyst. By optimizing the protective layer thickness, we observe increased efficiencies for photocatalytic oxygen evolution with a thick Ni electrocatalyst supported on n-Si. Our findings open avenues for the use of inexpensive electrocatalysts with favorable electroca...