Homogeneous photochemical water oxidation with metal salophen complexes in neutral media

Abstract

The development of water oxidation catalysts based on Earth-abundant metals that can function at neutral pH remains a basic chemical challenge. Here, we report that salophen complexes with Ni(II), Cu(II), and Mn(II) can catalyse photochemical water oxidation to molecular oxygen in the presence of [Ru(bpy)₃]²⁺ as a photosensitizer and Na₂S₂O₈ as an oxidant in phosphate buffer of pH 7.0. Experimental results including CV, SEM, EDS, ESI-MS, and DLS measurements on the metal salophen complex-catalysed water oxidation to oxygen suggest that the catalytic activity of the catalysts is molecular in origin.