Two Types of 2D Layered Iodoargentates Based on Trimeric [Ag3I7] Secondary Building Units and Hexameric [Ag6I12] Ternary Building Units: Syntheses, Crystal Structures, and Efficient Visible Light Responding Photocatalytic Properties

• Published in: Inorganic chemistry 2015-11, Vol.54 (22), p.10593-10603
• Main Authors: Lei, Xiao-Wu, Yue, Cheng-Yang, Zhao, Jian-Qiang, Han, Yong-Fang, Yang, Jiang-Tao, Meng, Rong-Rong, Gao, Chuan-Sheng, Ding, Hao, Wang, Chun-Yan, Chen, Wan-Dong, Hong, Mao-Chun
• Format: Article
• Language: English
• Subjects: Buildings; Cations; Energy gaps (solid state); Nickel; Photocatalysis; Semiconductors; Trimers; Two dimensional
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.5b01324

With mixed transition-metal-complex, alkali-metal, or organic cations as structure-directing agents, a series of novel two-dimensional (2D) layered inorganic–organic hybrid iodoargentates, namely, K x [TM­(2,2-bipy)3]2­Ag6I11 (TM = Mn (1), Fe (2), Co (3), Ni (4), Zn (5); x = 0.89–1) and [(Ni­(2,2-bipy)3]­[H-2,2-bipy]­Ag3I6 (6), have been solvothermally synthesized and structurally characterized. All the title compounds feature 2D microporous layers composed by [Ag3I7] secondary building units based on AgI4 tetrahedra. Differently, the [Ag3I7] trimers are directly interconnected via corner-sharing to form the 2D [Ag6I11]5– layer in compounds 1–5, whereas two neighboring [Ag3I7] trimers are initially condensed into a hexameric [Ag6I12] ternary building unit as a new node, which further self-assembles, leading to the 2D [Ag6I10]4– layer in compound 6. The UV–vis diffuse-reflectance measurements reveal that all the compounds possess proper semiconductor behaviors with tunable band gaps of 1.66–2.75 eV, which lead to highly efficient photocatalytic degradation activities over organic pollutants under visible light irradiation compared to that of N-dotted P25. Interestingly, all the samples feature distinct photodegradative speeds at the same reaction conditions, and compound 1 features the highest photocatalytic activity among the title phases. The luminescence properties, band structures, and thermal stabilities were also studied.