Constructing a novel Bi2SiO5/BiPO4 heterostructure with extended light response range and enhanced photocatalytic performance

To further extend the light response range of BiPO4 and meanwhile keep its strong photocatalytic oxidation ability, the design of a type-II heterojunction by coupling BiPO4 with a narrower band gap semiconductor of Bi2SiO5 as a novel and efficient photocatalytic catalyst has been successfully realized through a simple co-precipitate method. Moreover, under 365 nm UV light irradiation, pure BiPO4 shows no photo-activity, whereas the optimal Bi2SiO5/BiPO4 heterostructure exhibits highly enhanced photocatalytic activity than pure Bi2SiO5 in systems of photo-degradation over phenol and MB, which is 4.36 times and 1.13 times the values of pure Bi2SiO5. Experimental results reveal that the superior photocatalytic performance can be attributed to the synergetic effect of the evidently improved charge separation ability via the heterojunction, good crystallinity, expanded light absorbance and the moderate BET specific surface area.