College of Physics, Optoelectronics and Energy, Center for Energy Conversion Materials & Physics (CECMP), Jiangsu Key Laboratory of Thin Films, Soochow University , Suzhou 215006, People's Republic of China.
State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China , Chengdu 610054, People's Republic of China.
ACS Appl Mater Interfaces. 2016 May 18;8(19):12239-45. doi: 10.1021/acsami.6b03842. Epub 2016 May 9.
In a photoelectrochemical (PEC) cell for water splitting, the critical issue is charge separation and transport, which is usually completed by designing semiconductor heterojunctions. TiO2 anatase-rutile mixed junctions could largely improve photocatalytic properties, but impairs PEC water splitting performance. We designed and prepared two types of TiO2 heterostructures with the anatase thin film and rutile nanowire phases organized in different sequences. The two types of heterostructures were used as PEC photoanodes for water splitting and demonstrated completely opposite results. Rutile nanowires on anatase film demonstrated enhanced photocurrent density and onset potential, whereas strong negative performance was obtained from anatase film on rutile nanowire structures. The mechanism was investigated by photoresponse, light absorption and reflectance, and electrochemical impedance spectra. This work revealed the significant role of phase sequence in performance gain of anatase-rutile TiO2 heterostructured PEC photoanodes.
在光解水的光电化学（PEC）电池中，关键问题是电荷的分离和传输，这通常通过设计半导体异质结来完成。TiO2 锐钛矿-金红石混合结能够显著提高光催化性能，但会损害 PEC 水分解性能。我们设计并制备了两种具有不同序列的锐钛矿薄膜和金红石纳米线相的 TiO2 异质结构。这两种异质结构被用作光解水的 PEC 光阳极，并表现出完全相反的结果。锐钛矿薄膜上的金红石纳米线表现出增强的光电流密度和起始电位，而金红石纳米线结构上的锐钛矿薄膜则表现出强烈的负面性能。通过光响应、光吸收和反射以及电化学阻抗谱研究了其机制。这项工作揭示了在具有锐钛矿-金红石 TiO2 异质结构的 PEC 光阳极中，相序列对性能提升的重要作用。
