Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China.
Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China.
J Colloid Interface Sci. 2017 Dec 15;508:174-183. doi: 10.1016/j.jcis.2017.08.042. Epub 2017 Aug 16.
A central issue in understanding photo-redox catalysis is the facet-dependent charge movement behaviors that include bulk charge separation, surface charge transfer and interfacial charge migration. To get in-depth insight into these complicated processes steered by different exposing facets, herein BiOCl with exposed (001) and (010) facets engaged as the model are investigated. The BiOCl-(010) and BiOCl-(001) single-crystalline sheets are separately synthesized via hydrothermal and hydrolysis routes. In contrast to BiOCl-(010), BiOCl-(001) demonstrates highly promoted photo-redox performance for H generation and degradation of pollutants. The facet-dependent charge movement behaviors were surveyed by surface photovoltage spectroscopy (SPV), transient photocurrent, linear sweep voltammetry, continuous wavelength photocurrent, and electrochemical impedance spectrum (EIS). All the photoelectrochemical and photoelectric measurement results reflect that BiOCl-(001) exhibits superior charge separation and migration efficiencies in the whole charge movement process than the BiOCl-(010). Besides, a higher charge carrier density (3.1-fold enhancement) was also observed for BiOCl-(001) compared to BiOCl-(010). Our current work is expected to further our understanding on facet-dependent charge movement behaviors and offer new insight into design of high-performance photocatalytic/photoelectrochemical materials.
理解光氧化还原催化的一个核心问题是各方面依赖的电荷迁移行为，包括体相电荷分离、表面电荷转移和界面电荷迁移。为了深入了解不同暴露面指导的这些复杂过程，本文选择暴露（001）和（010）面的 BiOCl 作为模型进行研究。通过水热法和水解法分别合成了 BiOCl-(010)和 BiOCl-(001)单晶片。与 BiOCl-(010)相比，BiOCl-(001)在 H 生成和污染物降解方面表现出了更高的光氧化还原性能。通过表面光电压谱（SPV）、瞬态光电流、线性扫描伏安法、连续波长光电流和电化学阻抗谱（EIS）研究了各方面依赖的电荷迁移行为。所有光电化学和光电测量结果均表明，在整个电荷迁移过程中，BiOCl-(001)比 BiOCl-(010)具有更高的电荷分离和迁移效率。此外，与 BiOCl-(010)相比，BiOCl-(001)的载流子密度更高（提高了 3.1 倍）。我们的工作有望进一步了解各方面依赖的电荷迁移行为，并为设计高性能光催化/光电化学材料提供新的思路。
