A facile exfoliation-crystal growth route to multicomponent Ag2CO3/Ag-Ti5NbO14 nanohybrids with improved visible light photocatalytic activity

Abstract

Multicomponent Ag₂CO₃/Ag-layered Ti₅NbO₁₄ nanohybrids are synthesized by the crystal growth of silver carbonate on the surface of exfoliated layered titanoniobate 2D nanosheets. In the obtained nanohybrids, the spherical Ag₂CO₃ nanoparticles with a size of 5–10 nm are immobilized on the surface of the titanoniobate nanosheets with partial formation of neutral Ag metal caused by electron transfer from anionic titanoniobate nanosheets to silver cations. An electronic coupling between Ag₂CO₃/Ag and Ti₅NbO₁₄ nanosheets leads to a remarkable enhancement of visible light absorption and a significant depression of electron–hole recombination. The present Ag₂CO₃/Ag-layered Ti₅NbO₁₄ nanohybrids show much higher visible light photocatalytic activity than the unhybridized Ag₂CO₃, underscoring the beneficial effect of hybridization with metal oxide nanosheets on the photocatalytic activity of silver oxosalts. Before and after the photoreaction, the crystal structure and crystal morphology of the Ag₂CO₃/Ag-layered Ti₅NbO₁₄ nanohybrids remain unchanged, highlighting the excellent photostability of these materials. All the present experimental findings clearly demonstrate the usefulness of the exfoliation-crystal growth method in exploring novel efficient visible light active photocatalysts.