Surface doping of Bi4Ti3O12 with S: Enhanced photocatalytic activity, mechanism and potential photodegradation application

In this study, we have doped S element in the surface of BTO crystals and improve their photocatalytic activities in decomposing organic pollutants. The as-derived Sdoped-BTO photocatalysts were systematically analyzed by various techniques. It is demonstrated that S element is successfully doped in the BTO surface, and the Sdoped-BTO samples exhibit enhanced visible-light adsorption and separation efficiency of photognerated electron-hole pairs. The photocatalytic activities between the x%S-BTO samples were compared by simulated-sunlight driving photodegradation of MB, revealing that 3.3%S-BTO is the optimal photocatalyst having a photocatalytic activity about 10.1 times higher than that of pristine BTO. To promote the potential application of the optimal 3.3%S-BTO photocatalyst, its photocatalytic performances were further investigated, including effects of inorganic anions and pH values on the MB photodegradation, and photodegradation of other organic pollutants (TBBPA, CIP, TC, MO/RhB/MB mixture dyes). The enhanced photocatalytic mechanism for the Sdoped-BTO photocatalysts was proposed and discussed.