A facile synthesis of C3N4-modified TiO2 nanotube embedded Pt nanoparticles for photocatalytic water splitting

Construction of high-efficient and low-cost heterostructure photocatalyst is crucial for hydrogen production in solar driven water splitting. Herein, g-C3N4-modified TiO2 nanotubes (TNTs) with confined Pt nanoparticles were prepared via a facile two-step process. The results of structure characterizations by XRD, TEM, and XPS reveal that Pt nanoparticles with the average size of 2–3 nm are embedded in the inner cavity of the TiO2 nanotube, and amorphous g-C3N4 is attached to the outer wall of anatase TNTs. The as-prepared g-C3N4/TNTs@Pt ternary composite displays an enhanced visible light-induced absorbance capacity and improved charge carrier recombination rate than that of pure TNTs. The photocatalytic performance is evaluated by hydrogen evolution from water splitting by using methanol as sacrifice agent under solar light illumination. Compared with TNTs@Pt and g-C3N4/Pt photocatalysts, the as-prepared ternary nanocomposite exhibits the highest photocatalytic performance with a H2 evolution rate of 15.36 mmol h−1 g−1. A possible mechanism of photocatalytic H2 production over the ternary g-C3N4/TNTs@Pt composite is also proposed. This work not only provides a promising low-cost heterostructure candidate for water splitting, but also paves the way to rational design high-performance photocatalysts in solar-to-fuel conversion.