Electrochemical behavior and assembly of tetranuclear Dawson-derived sandwich compound [Cd4(H2O)2(As2W15O56)2]16− on 4-aminobenzoic acid modified glassy carbon electrode

A multilayer assembly of two mixed-valence Mn16-containing polyanions and study of their electrocatalytic activities towards water oxidation

Herein, two mixed-valence Mn16-containing polyanions, (Mn16) [MnIII10MnII6O6(OH)6(PO4)4(A-a-SiW9O34)4]28- (Mn16-Cs) and [MnIII4MnII12(OH)12(PO4)4(A-a-SiW9O34)4]28- (Mn16-Rb), were successfully fabricated on an indium tin oxide (ITO)-coated glass electrode and a glass carbon electrode (GCE) by a layer-by-layer assembly method. Moreover, four composite films, i.e. [PDDA/Mn16-Cs]n, [PDDA/Mn16-Rb]n, [Mn16-Cs/Rubpy]n, and [Mn16-Rb/Rubpy]n (PDDA: poly(diallyldimethylammonium chloride); Rubpy: tris(2,2'-bipyridyl)ruthenium(ii) chloride; n = 1-10), were constructed for comparison and characterized by UV-visible spectroscopy, cyclic voltammetry (CV), and X-ray photoelectron spectroscopy (XPS). Their electrocatalytic activities towards water oxidation were studied under the same experimental conditions. The results of the controlled experiments indicate that (1) all the four films exhibit expected electrocatalytic activities towards water oxidation; (2) the electrocatalytic activity of Mn16-Cs is better than that of Mn16-Rb in solution and composite films; and (3) the electrocatalytic activities of the composite film [Mn16/Rubpy]n are better than those of the composite film [PDDA/Mn16]n.

A survey of the different roles of polyoxometalates in their interaction with amino acids, peptides and proteins

This perspective provides a comprehensive description of the different roles of POMs in their interaction with relevant biological molecules.