Structure and stability of Belladona Mottle Virus

Abstract

Surface hydroxylation is not the only criterion to obtain higher catalytic activity in water photolysis mediated by TiO?. Neutralisation of surface hydroxyls on TiO? by alkali may produce Ti–O? groups which trap the photogenerated holes to form Ti–O• radicals and subsequently peroxotitanium species at the surface, leading to evolution of O?. The presence of crystallographic defects (surface) on particles with poor crystallinity, prepared by other routes, may broaden the energy states of Ti–O•. The resulting surface state “bands” may enable the hole transfer to species in solution, such as O?/OH?. Whereas, for monocrystalline particles free of defects, the corresponding surface states may have minimum energy spread so that charge transfer is possible only to hole-scavengers, such as EDTA or TEOA. Platinised rutile powders are as equally active as anatase in sacrificial systems.