Unravelling the interfacial interaction in mesoporous SiO(2)@nickel phyllosilicate/TiO(2) core–shell nanostructures for photocatalytic activity

Core–shell based nanostructures are attractive candidates for photocatalysis owing to their tunable physicochemical properties, their interfacial contact effects, and their efficacy in charge-carrier separation. This study reports, for the first time, on the synthesis of mesoporous silica@nickel phyllosilicate/titania (mSiO(2)@NiPS/TiO(2)) core–shell nanostructures. The TEM results showed that the mSiO(2)@NiPS composite has a core–shell nanostructure with a unique flake-like shell morphology. XPS analysis revealed the successful formation of 1:1 nickel phyllosilicate on the SiO(2) surface. The addition of TiO(2) to the mSiO(2)@NiPS yielded the mSiO(2)@NiPS/TiO(2) composite. The bandgap energy of mSiO(2)@NiPS and of mSiO(2)@NiPS/TiO(2) were estimated to be 2.05 and 2.68 eV, respectively, indicating the role of titania in tuning the optoelectronic properties of the SiO(2)@nickel phyllosilicate. As a proof of concept, the core–shell nanostructures were used as photocatalysts for the degradation of methyl violet dye and the degradation efficiencies were found to be 72% and 99% for the mSiO(2)@NiPS and the mSiO(2)@NiPS/TiO(2) nanostructures, respectively. Furthermore, a recyclability test revealed good stability and recyclability of the mSiO(2)@NiPS/TiO(2) photocatalyst with a degradation efficacy of 93% after three cycles. The porous flake-like morphology of the nickel phyllosilicate acted as a suitable support for the TiO(2) nanoparticles. Further, a coating of TiO(2) on the mSiO(2)@NiPS surface greatly affected the surface features and optoelectronic properties of the core–shell nanostructure and yielded superior photocatalytic properties.