Abstract The rapid recombination and poor redox capability of photoinduced charge carriers seriously impede the photocatalytic activity. Herein, a direct Z-scheme photocatalyst was fabricated by selectively depositing Ag6Si2O7 nanoparticles (NPs) on the {0 4 0} facets of BiVO4. Owing to the facet-dependent band structure of BiVO4, the photoinduced electrons and holes can be pre-separated upon photoillumination and transfer to {0 4 0} and {1 1 0} facets of BiVO4, respectively. A rapid combination of the separated electrons at the {0 4 0} facets of BiVO4 with holes of the Ag6Si2O7 NPs then takes place triggering a direct Z-scheme photocatalysis. Such a charge pre-separation triggered by the faceted BiVO4, together with Z-scheme at the interface warrants not only effective photoinduced charge separation but also excellent redox capability owing to the increased redox potential. The photocatalytic rate constant of the optimum BiVO4{0 4 0}/Ag6Si2O7 heterostructure is 28.2 and 17.2 times higher than those of pristine BiVO4 and Ag6Si2O7, respectively. This study offers a new insight for constructing direct Z-scheme photocatalysts with high degradation efficiency based on facet-controlled crystals.

中文翻译：

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BiVO4{040}/Ag6Si2O7光催化剂中电荷预分离和直接Z型桥的协同促进有机污染物降解

摘要 光生载流子的快速复合和较差的氧化还原能力严重阻碍了光催化活性。在此，通过在 BiVO4 的 {0 4 0} 面上选择性沉积 Ag6Si2O7 纳米颗粒 (NPs) 来制造直接 Z 型光催化剂。由于BiVO4 的面相关能带结构，光生电子和空穴可以在光照射下预先分离并分别转移到BiVO4 的{0 4 0} 和{1 1 0} 面。在 BiVO4 的 {0 4 0} 面分离的电子与 Ag6Si2O7 NPs 的空穴快速结合，然后触发直接 Z 型光催化。这种由多面 BiVO4 触发的电荷预分离，与界面处的 Z 方案一起，不仅保证了有效的光诱导电荷分离，而且由于氧化还原电位的增加，还保证了优异的氧化还原能力。最佳BiVO4{0 4 0}/Ag6Si2O7异质结构的光催化速率常数分别比原始BiVO4和Ag6Si2O7高28.2倍和17.2倍。该研究为构建基于面控制晶体的具有高降解效率的直接 Z 型光催化剂提供了新的见解。