Jones Daniel R, Phillips Robert, Gannon William J F, Rome Bertrand, Warwick Michael E A, Dunnill Charles W
Energy Safety Research Institute (ESRI), Swansea University Bay Campus, Swansea, SA1 8EN, UK.
Sci Rep. 2019 Aug 9;9(1):11573. doi: 10.1038/s41598-019-48069-5.
Through a facile solvothermal procedure, a CdS/WO nanocomposite has been synthesised which exhibits photocapacitive behaviour under white light illumination at a radiant flux density of 99.3 mW cm. Photoelectrochemical experiments were undertaken to examine the self-charging properties of the material and to develop an understanding of the underlying electronic band structure responsible for the phenomenon. By employing XPS, UPS and UV-Vis diffuse reflectance spectroscopy for further characterisation, the ability of the composite to generate current following the removal of incident light was related to the trapping of photoexcited electrons by the WO component. The presence of WO yielded an order of magnitude increase in the transient photocurrent response relative to CdS alone, an effect attributed to the suppression of electron-hole recombination in CdS due to hole transfer across the CdS/WO interface. Moreover, current discharge from the material persisted for more than twenty minutes after final illumination, an order of magnitude improvement over many existing binary composites. As a seminal investigation into the photocapacitive characteristics of CdS/WO composites, the work offers insight into how the constituent materials might be utilised as part of a future self-charging solar device.
通过简便的溶剂热法合成了一种CdS/WO纳米复合材料，该复合材料在99.3 mW cm的辐射通量密度的白光照射下表现出光电电容行为。进行了光电化学实验，以研究该材料的自充电特性，并深入了解导致该现象的潜在电子能带结构。通过采用XPS、UPS和紫外-可见漫反射光谱进行进一步表征，复合材料在去除入射光后产生电流的能力与WO组分对光激发电子的捕获有关。相对于单独的CdS，WO的存在使瞬态光电流响应增加了一个数量级，这一效应归因于通过CdS/WO界面的空穴转移抑制了CdS中的电子-空穴复合。此外，在最终光照后，材料的电流放电持续了二十多分钟，比许多现有的二元复合材料有了一个数量级的改善。作为对CdS/WO复合材料光电电容特性的开创性研究，这项工作为如何将组成材料用作未来自充电太阳能装置的一部分提供了见解。
