Hollowsphere Nanoheterojunction of g‑C3N4@TiO2 with High Visible Light Photocatalytic Property

In this work, g-C3N4@TiO2 nanostructures with hollow sphere morphology, small grain size, high crystalline quality, and high surface area are successfully synthesized by the annealing method using melamine and hollowsphere precursor, which could be a universal method to synthesis hollow sphere nanoheterojunction. Excellent photocatalytic property was observed from the as-prepared g-C3N4@TiO2 nanostructure with 466.43 μmol·g–1·h–1 hydrogen generation rate under visible light irradiation (>420 nm), which was 5.5 times as much as the control couple, nanoparticle nanoheterojunction g-C3N4@TiO2. No apparent deactivation was found during the follow-up cycle performance test. The special morphology and the heterojunction construction contribute to both visible light absorption and photogenerated electron–hole pair separation efficiency and finally to the photocatalytic property. The content of g-C3N4 was proved to be an important parameter for the promotion of the photocatalytic property. Overlarge content may lead to lower photogenerated electron–hole pair separation efficiency.