Nonstoichiometric Bi2O3: efficient visible light photocatalyst

A facile, simple and economical route to induce surface defects on bulk bismuth oxide (Bi2O3) via thermal treatment in a vacuum is introduced. This results in a Bi2O3/Bi2O3+x novel composite with variable oxidation states of Bi. These surface states enhance visible light photocatalytic activity and photostability of bulk oxide.