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Unprecedented {Fe 14 }/{Fe 10 } Polyoxotungstate‐Based Nanoclusters with Efficient Photocatalytic H 2 Evolution Activity: Synthesis, Structure, Magnetism, and Electrochemistry
Author(s) -
Singh Vikram,
Chen Zhiyuan,
Ma Pengtao,
Zhang Dongdi,
Drew Michael G. B.,
Niu Jingyang,
Wang Jingping
Publication year - 2016
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201601453
Subject(s) - polyoxometalate , thermogravimetric analysis , nanoclusters , crystallography , electrochemistry , cluster (spacecraft) , chemistry , magnetism , antiferromagnetism , crystal structure , x ray photoelectron spectroscopy , magnetic susceptibility , caesium , inorganic chemistry , catalysis , nuclear magnetic resonance , biochemistry , physics , organic chemistry , electrode , quantum mechanics , computer science , programming language , condensed matter physics
Novel Fe 10 and Fe 14 clusters [Rb 9 Cs 4 H 37 Fe 10 O 34 (A‐α‐PW 9 O 31 ) 3 (OH) 3 ] ⋅ 36 H 2 O ( 1 ) and [H 3 Rb 3 Fe 14 (OH) 12 (PO 4 ) 6 (B‐α‐PW 9 O 34 ) 2 ] ⋅ 21 H 2 O ( 2 ) were synthesized and characterized in the solid state by single‐crystal X‐ray diffraction, IR spectroscopy, thermogravimetric analysis (TGA), and magnetic studies, and in solution by electrochemistry. Cluster 1 is a decameric Fe III polyanionic cluster encapsulating a cesium atom in the center. Cluster 2 is a unique tetradecanuclear Fe III sandwich structure with phosphate‐linked units featuring two quasicubic Fe 4 O 4 moieties. Apparently, 2 has the highest nuclearity of all known Fe III sandwich‐type polyoxometalate clusters. Clusters 1 and 2 also act as photocatalysts with platinum as cocatalyst for H 2 evolution from light‐driven water splitting. Changes in the cyclovoltammetric patterns with variations in pH were observed for 1 and 2 , most likely due to intermolecular interactions among the high‐nuclearity Fe III cluster cores and subsequent changes in the acid–base properties of the two reduced POMs. Magnetic studies provide evidence of antiferromagnetic interactions in 1 and 2 . TGA showed that complexes 1 and 2 decompose between 580 and 590 °C.