Zhang Miaomiao, Chu Xianqiang, Zhang Hui, Huang Fangzhi, Liu Pianpian, Li Shikuo
AnHui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials, Key Laboratory of Structure and Functional Regulation of Hybrid Materials (Anhui University) Ministry of Education, School of Chemistry and Chemical Engineering, School of Physics and Materials Science, Institute of Physical Science and Information Technology, Anhui University, Hefei, 230601, P. R. China.
Phys Chem Chem Phys. 2021 Apr 22;23(15):9347-9356. doi: 10.1039/d0cp06489k.
Manipulating the charge carrier transport in photoactive materials is a big challenge toward high efficiency solar water splitting. Herein, we designed a hierarchical ZnxCd1-xS architecture for tuning the interfacial charge transfer kinetics. The in situ growth of ZnxCd1-xS nanoflakes on ZnO backbones provided low interfacial resistance for charge separation. With this special configuration, the optimized Zn0.33Cd0.67S photoanode achieved significantly enhanced performance with a photocurrent density of 10.67 mA cm-2 at 1.23 V versus RHE under AM1.5G solar light irradiation, which is about 14.1 and 2.5 times higher than that of the pristine ZnO and CdS nanoparticle decorated ZnO photoanodes, respectively. After coating a thin SiO2 layer, the photostability of the hierarchical Zn0.33Cd0.67S photoanode is greatly enhanced with 92.33% of the initial value retained under 3600 s continuous light illumination. The prominent PEC activity of the hierarchical ZnxCd1-xS nanorod arrays can be ascribed to an enhanced charge transfer rate aroused by the binder-free interfacial heterojunction, and the improved reaction kinetics at the electrode-electrolyte interface, which is evidenced by electrochemically active surface area measurements and intensity modulated photocurrent spectroscopy analysis. This interfacial heterojunction strategy provides a promising pathway to prepare high performance photoelectrodes.
在光活性材料中调控电荷载流子传输对于高效太阳能水分解而言是一项巨大挑战。在此，我们设计了一种分级结构的ZnxCd1-xS架构以调节界面电荷转移动力学。ZnxCd1-xS纳米片在ZnO骨架上的原位生长为电荷分离提供了低界面电阻。凭借这种特殊结构，优化后的Zn0.33Cd0.67S光阳极在AM1.5G太阳光照射下，相对于可逆氢电极在1.23 V时实现了显著增强的性能，光电流密度达到10.67 mA cm-2，分别比原始ZnO和CdS纳米颗粒修饰的ZnO光阳极高出约14.1倍和2.5倍。在涂覆一层薄的SiO2层后，分级结构的Zn0.33Cd0.67S光阳极的光稳定性大大增强，在3600 s连续光照下保留了92.33%的初始值。分级结构的ZnxCd1-xS纳米棒阵列突出的光电化学活性可归因于无粘结剂界面异质结引起的电荷转移速率增强，以及电极 - 电解质界面处反应动力学的改善，这通过电化学活性表面积测量和强度调制光电流光谱分析得到了证实。这种界面异质结策略为制备高性能光电极提供了一条有前景的途径。
