A Polyoxometalate-Based Inorganic Porous Material with both Proton and Electron Conductivity by Light Actuation: Photocatalysis for Baeyer–Villiger Oxidation and Cr(VI) Reduction

作者：Si Chen, Pengtao Ma, Qiuxia Han, Jiachen Jiao, Wei Du, Jingpin Wu, Mingxue Li, Jingyang Niu · 发表于：Inorganic Chemistry · 年份：2020 · DOI：10.1021/acs.inorgchem.0c02658 · 被引用次数：43 · 研究领域：Polyoxometalates: Synthesis and Applications、Metal-Organic Frameworks: Synthesis and Applications、Covalent Organic Framework Applications

Two-dimensional (2D) crystalline porous materials with designable structures and high surface areas are currently a hot research topic in the field of proton- and electron-conducting materials, which provide great opportunities to orderly accommodate carriers in available spaces and to accurately understand the conducting path. The 2D dual-conductive inorganic framework [Co(H 2 O) 6 ] 2 {[Co(H 2 O) 4 ] 4 [WZn 3 (H 2 O) 2 (ZnW 9 O 34 ) 2 ]}·8H 2 O ( Co 6 Zn 5 W 19 ) is synthesized by combining [WZn 3 (H 2 O) 2 (ZnW 9 O 34 ) 2 ] 12– ( Zn 5 W 19 ) and a Co(II) ion via a hydrothermal method. Due to the presence of a consecutive H-bonding network, electrostatic interactions, and packing effects between the framework and guest molecules, Co 6 Zn 5 W 19 displays a high proton conductivity (3.55 × 10 –4 S cm –1 under 98% RH and 358 K) by a synergistic effect of the combined components. Additionally, a photoactuated electron injection into the semiconducting materials is an important strategy for switching electronic conductivity, because it can efficiently reduce the frameworks without destroying the crystallinity. I – V curves of a tablet of Co 6 Zn 5 W 19 in the reduced and oxidized states yield conductivities of 1.26 × 10 –6 and 5 × 10 –8 S cm –1, respectively. Moreover, Co 6 Zn 5 W 19 is also successfully applied in the photocatalytic reduction of the toxic Cr(VI) metal ion by utilizing its excellent electronic storage capacity and Baeyer–Villiger (BV) oxidation in a molecular ox...