Visible-light activated photocatalytic effect of glass and glass ceramic prepared by recycling waste slag with hematite

Abstract

Abstract A relationship between the local structure and the visible-light activated photocatalytic effect was investigated in the glass and glass ceramics prepared by recycling waste slag, which was discharged from a Tokyo Household Garbage Combustion Plant. For the preparation of a homogeneous sample of waste slag recycled glass, (WSRG), 10 wt% of Na 2 CO 3 and 10–50 wt% of Fe 2 O 3 were added. 57 Fe-Mössbauer spectra of WSRG recorded at liquid nitrogen temperature showed three types of magnetic hfs ; one due to Fe II ( O h ) with δ of 1.21 mm s −1 and H int of 46.7 T, one due to Fe III ( O h ) with δ of 0.46 mm s −1 and H int of 44.1 T, and the other due to Fe III ( T d ) with δ of 0.38 mm s −1 and H int of 47.8 T. They were superimposed on a relaxation spectrum due to superparamagnetic hematite. Methylene blue (MB) degradation test with 40 mg of the heat treated WSRG (50 wt% Fe 2 O 3 ), under the visible-light irradiation for 6 h showed a marked decrease in the concentration of MB from 20 to 7.7 μmol L −1 with a rate constant ( k ) of 2.7×10 −3 min −1 which was close to the k , 9.26×10 −3 min − 1 , recently obtained in 15Na 2 O⋅15CaO⋅40Fe 2 O 3 ⋅ 11Al 2 O 3 ⋅19SiO 2 glass.