Visible-light absorptivity of a zincoxysulfide (ZnOxS_(1_x)) composite semiconductor and its photocatalytic activities for degradation of organic pollutants under visible-light irradiation

摘要

This work reports the development of a visible-light sensible photocatalyst and the photocatalytic degradation of organic pollutants under visible-light irradiation.A composite semiconductor of ZnS and ZnO was prepared through co-precipitation process of Zn(NO3)2 in the mixed solution of aqueous Na2S and NaOH followed by calcination at 400 °C in N2 atmosphere:It was revealed that the composite semiconductor was a solid solution of ZnS and ZnO,a zincoxy sulfide (ZnO_xS_(1-x)) having advanced visible-light absorptivity.It was assured that the visible-light absorptivity was caused by modification of band structure while the solid solution had been prepared,thus we suggested a reasonable band structure model involved in a zincoxysulfide.To observe its photocatalytic activity under visible-light illumination,photodegradation test was done and we confirmed that zincoxysulfide showed predominant photocatalytic activity due to its superior visible-light absorptivity to pure ZnS and ZnO.