Highly functional SnO2 coated PZT core–shell heterostructures as a visible light photocatalyst for efficient water remediation

• Visible light driven SnO2 coated PZT spheres were synthesized by two step solvothermal method.
• The EDS mapping shows the uniform coating of SnO2 over PZT spheres.
• Visible light photocatalytic activities for the degradation of Toluidine Blue O dye.
• SnO2/PZT spheres exhibited excellent chemical stability and efficient charge separation.

Highly quality SnO2/PZT core–shell heterostructure has been successfully synthesized using a two-step solution method for use in semiconductor-sensitized photocatalysis. The control of SnO2 shell thickness was achieved by simply tuning Sn molar ratio which consequently affects the visible-light absorption properties and photocatalytic performance of the SnO2/PZT core–shell heterostructure. The as-synthesized SnO2/PZT core–shell heterostructure exhibited superior photocatalytic activity under both visible and UV light compared to the bare PZT. The enhanced photocatalytic activity of SnO2/PZT core–shell heterostructure could be attributed to the formation of the heterojunction between the two, which improves the separation of photogenerated electrons and holes and light absorbance under visible and UV light illumination. This enhanced charge separation efficiency is verified by electrochemical impedance spectroscopy. Moreover, the SnO2/PZT core–shell heterostructure could be easily recycled while maintaining its photocatalytic activity up to 10 cycles.