Synthesis and photocatalytic activity of TiO2@CdS and CdS@TiO2 double-shelled hollow spheres

► Novel microporous TiO2@CdS and CdS@TiO2 double-shell hollow spheres (DHS) were synthesized. ► Both TiO2@CdS and CdS@TiO2 DHS exhibit wide-absorption response in the solar spectrum and enhanced photocatalytic activity under visible-light illumination. ► The mechanism of photocatalysis occurred on TiO2@CdS and CdS@TiO2 DHS under visible light is discussed.