Interfacial Charge Separartion in the Photoreduction of Water: Effects of Colloidal Silica

Abstract

It has been confirmed that colloidal silica can retard reverse electron transfer in the photochemical system water/ tris (2,2′- bipyridine )ruthenium dication/triethanolamine/zwitterionic viologen . However, the beneficial effect of silica diminishes as the concentration of the electron donor ( triethanolamine ) increases. Substantially higher yields of hydrogen have been obtained with 2,2′,6,6′-tetramethyl-1,1′- di (3-sulfonatopropyl)-4,4′-bipyridinediium which is more stable and has a more favourable potential than previously used electron-transfer agents.