Mechanism Insight into an Unprecedented Dual Series‐Parallel Photocharge Separation in Quaternary Cu<sub>2</sub>O Facet Junctions
Jie Cui, Xin Zhang, Hongwei Huang, Man Yang, Bian Yang, Qing Yang, Shuhua Liang, Shaodong Sun
Abstract
Abstract Uncovering the contribution of anisotropic crystal facets in single‐crystalline photocatalysts is still a challenge in fundamental study. Here, the mechanism underlying facet junction‐dependent photocharge separation in polyhedral Cu 2 O is demonstrated, which is beneficial for understanding why 50‐faceted Cu 2 O exhibiting quaternary {100}/{110}/{111}/{522} facet junction possesses an enhanced photodegradation activity toward tetracycline than that of the 26‐faceted Cu 2 O exhibiting ternary {100}/{110}/{111} and 18‐faceted Cu 2 O exhibiting binary {100}/{110} facet junction. Density functional theory (DFT) calculations and selective photodeposition results confirm that hierarchical facet junctions are formed in a 50‐faceted Cu 2 O, which could be regarded as one parallel connection between binary {110}/{111} and ternary {110}/{522}/{100} series facet junction for conduction band minimum, and another parallel connection between binary {100}/{522} and ternary {111}/{110}/{522} series facet junction for valence band maximum, leading to an unprecedented dual series‐parallel transfer pathway for more efficiently improved photocharge separation. Hopefully, this study would be a beneficial guideline for scientific researchers currently concentrating on the facet junction engineering of polyhedral photocatalysts.