2D graphitic-C3N4 hybridized with 1D flux-grown Na-modified K2Ti6O13 nanobelts for enhanced simulated sunlight and visible-light photocatalytic performance

Abstract

Two-dimensional (2D) graphitic-C₃N₄ (g-C₃N₄) was successfully hybridized with one-dimensional (1D) flux-grown Na-modified K₂Ti₆O₁₃ nanobelts (Na-K₂Ti₆O₁₃ NBs) for the first time to construct novel 1D/2D Na-K₂Ti₆O₁₃/g-C₃N₄ heterostructured photocatalysts using a facile mixing–calcination method. The heterostructured Na-K₂Ti₆O₁₃/g-C₃N₄ composites with three-dimensional (3D) hybrid architectures exhibited a remarkably enhanced photocatalytic efficiency for organic pollutant degradation in comparison with pure Na-K₂Ti₆O₁₃ and g-C₃N₄ under both simulated sunlight and visible-light irradiation (λ > 420 nm), which could be mainly attributed to the synergistic effects between Na-K₂Ti₆O₁₃ and g-C₃N₄ including more efficient interfacial charge transfer, longer lifetimes and the stronger oxidation and reduction ability of photogenerated charge carriers, fundamentally originating from the formation of Na-K₂Ti₆O₁₃/g-C₃N₄ heterojunctions based on the well-matched energy-band structures. Moreover, the Na-K₂Ti₆O₁₃/g-C₃N₄ hybrids showed good stability and reusability for the photocatalytic degradation of organic pollutants. Finally, the possible mechanisms responsible for the improved simulated sunlight and visible-light photocatalytic performance were also investigated, respectively, based on the results of PL spectra, time-resolved fluorescence decay spectra, radical species trapping experiments, ESR spectra and PL-TA measurements. Overall, this work will not only be beneficial for the design and development of more efficient visible-light-responsive g-C₃N₄-based composites for solar energy conversion and environmental remediation but will also be influential in optimizing the visible-light photocatalytic activity of wide-band-gap 1D titanate nanomaterials to meet the requirements of practical applications.