Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, USA.
J Am Chem Soc. 2011 Mar 2;133(8):2398-401. doi: 10.1021/ja110741z. Epub 2011 Feb 9.
We report the highest external quantum efficiency measured on hematite (α-Fe(2)O(3)) without intentional doping in a water-splitting environment: 46% at λ = 400 nm. This result was enabled by the introduction of TiSi(2) nanonets, which are highly conductive and have suitably high surface areas. The nanonets serve a dual role as a structural support and an efficient charge collector, allowing for maximum photon-to-charge conversion. Without the addition of any oxygen-evolving catalysts, we obtained photocurrents of 1.6 and 2.7 mA/cm(2) at 1.23 and 1.53 V vs RHE, respectively. These results highlight the importance of charge transport in semiconductor-based water splitting, particularly for materials whose performance is limited by poor charge diffusion. Our design introduces material components to provide a dedicated charge-transport pathway, alleviating the reliance on the materials' intrinsic properties, and therefore has the potential to greatly broaden where and how various existing materials can be used in energy-related applications.
我们报告了在水分解环境中无故意掺杂的情况下测量到的赤铁矿（α-Fe（2）O（3））的最高外量子效率：在 λ = 400nm 时为 46%。这一结果得益于 TiSi（2）纳米网的引入，它具有高导电性和适当高的表面积。纳米网同时起到结构支撑和高效电荷收集器的作用，从而实现最大的光子到电荷的转换。在没有添加任何析氧催化剂的情况下，我们在 1.23 和 1.53V 相对于 RHE 时分别获得了 1.6 和 2.7mA/cm（2）的光电流。这些结果突出了电荷输运在基于半导体的水分解中的重要性，特别是对于那些由于电荷扩散不良而性能受限的材料。我们的设计引入了材料组件，提供了专门的电荷输运途径，减轻了对材料固有特性的依赖，因此有可能大大拓宽各种现有材料在能源相关应用中的应用范围和方式。
