PHOTOCHEMICAL FORMATION OF HYDROGEN PEROXIDE FROM WATER. PART II. IN PRESENCE OF BASIC ZINC CARBONATE AND OXIDES OF CADMIUM, TIN AND THORIUM

The photochemical formation of hydrogen peroxide from water has been found to take place in presence of basic zinc carbonate. A shady of this reaction in presence of zinc carbonate and zinc oxide in the ultra­violet light from a mercury-vapour lamp has shown that zinc carbonate is more photoactive than zinc oxide in this reaction. Besides cadmium oxide which is already known to sensitise this reaction (vide 'Chemical Action of Light' by N. R. Dhar, p. 263), stannic oxide and thorie have also been found to act as photosensitisers. A com­parative study of the photoactivity of these three oxides has been carried out.