Photocatalytic reduction of Ag2SO4 by electrostatic complexes formed by tetracationic zinc porphyrins and tetracobalt Dawson-derived sandwich polyanion

New complexes based on electrostatic interactions between the tetracobalt Dawson-derived sandwich polyanion [Co4(H2O)(OH)(P2W15O56)2]17− and the tetracationic zinc porphyrins, ZnTMPyP4+ or ZnOETPyP4+, are formed in aqueous solutions. In these complexes, porphyrins can be excited by visible light and then play the role of photosensitizers able to give electrons to polyoxometalate. Consequently, these complexes exhibit photocatalytic behaviour in the visible domain. Indeed, the photocatalytic reduction of silver ions in the presence of these complexes and propan-2-ol is observed in aerated and deaerated aqueous solutions. The formed silver nanoparticles are stable in air conditions without illumination.

The photocatalytic behaviour of new porphyrin–polyoxometalate complexes for the reduction of silver ions in the presence of propan-2-ol was investigated and compared to that of the precursor compounds. In these complexes, porphyrins can be excited by visible light and then play the role of photosensitizers able to give electrons to polyoxometalate.Figure optionsDownload high-quality image (110 K)Download as PowerPoint slide