Electrochemical Properties of Polyoxometalate (H3PMo12O40)-Functionalized Graphitic Carbon Nitride (g-C3N4)

Abstract

A functionalized polyoxometalate/graphitic carbon nitride (PMo 12 /g-C 3 N 4) composite has been constructed to promote direct electron and ion exchange based on a facile, rapid wetness incipient method. The PMo 12 displayed a natural affinity towards the carbon support which facilitated enhanced reversible redox processes with surface-controlled electron diffusion. The g-C 3 N 4functionalized PMo 12 composite promoted effective oxidation and reduction of the Keggin molecule addenda atoms with reduced overpotential without the mediation of a polymeric linker to promote their exposure and interaction. The g-C 3 N 4 offered increased surface area for anchoring PMo 12 , structural stability at increased temperatures, and repeated cycling as well as control of the density and position of PMo 12 as probed by scanning electron microscopy and nuclear magnetic resonance spectroscopy, respectively. These results demonstrate that PMo 12 clusters are sensitive to their local environment, including the interaction with the support, which stimulated enhanced current mobility.

Polyoxometalates‐Based Ionic Liquids (POMs‐ILs) for Electrochemical Applications

“…The cyclic voltammetry studies were performed at different scan rates from 20 to 500 mV/s in several electrochemical windows [(0.4/−3/2/0.4), (0.4/−1.2/0.4), (0.4/−0.74/0.4), (0.4/−0.36/0.4) and (0.4/−0.05/0.4)] and in similar condition. Three reversible electron transfers (ET) can be observed for all POM‐ILs (see Figures and S4) which agrees with the previously described in the literature . These redox processes can be summarized in the following equations…”

Melem Nanorectangular Prism-Modified {Mo72Fe30} Nanocapsule as a Visible-Light-Assisted Photocatalyst for Catalase-Like Activity

“…According to the redox potentials presented in Scheme A, the photogenerated electrons and holes in Melem-modified Keplerate are active redox agents to efficiently convert H 2 O 2 to H 2 O and O 2 , respectively. It should be noted that the PET process found for M/K can also be expected with the participation of destructed products because the LUMO level of Melem is still higher than that of iron molybdate, and simple POMs as possible products of the Keplerate destruction. − …”

Characterizing photocatalysts for water splitting: from atoms to bulk and from slow to ultrafast processes

“…291 Cyclic voltammetry is also a routine method for the electrochemical characterization of molecular and supramolecular photocatalysts in order to identify the influence of the microenvironment (e.g., ligands) on the redox potential of the transition metal centres, the electron transfer characteristic (i.e., overpotentials) and -in case of binding the catalyst to a solid electrode surface -the surface coverage and the influence of attachment on the electrochemical behaviour. Cyclic voltammetry has been employed on various photocatalysts among those, biomimetic derived hydrogenase catalysts, 155,[292][293][294] POMs [295][296][297] and their stability in dependence of pH, 298,299 and supramolecular catalysts. [300][301][302][303] Habermehl et al recently demonstrated a panchromatic osmium photocatalyst [(tbbpy) 2 -Os(tpphz)PtI 2 ] 2+ (termed OsPt)-structure shown in Fig.…”