▎ 摘　　要

A La2Ti2O7/graphene (GR) nanocomposite with intimate interfacial contact and a large contact area is synthesized by a facile electrostatic self-assembly approach. The nanocomposite is characterized by Xray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy and photoluminescence (PL) spectroscopy. The La2Ti2O7/GR nanocomposite exhibits the highest H-2 production rate when used in photocatalytic water splitting, with an improvement of 5.7 and 4.9 times relative to pure La2Ti2O7 and La2Ti2O7/GR-H that was prepared without surface charge modification, respectively. In addition, the transient photocurrent responses and electrochemical impedance spectroscopy (EIS) results indicate that the La2Ti2O7/GR nanocomposite exhibits more effective separation of photogenerated electron-hole pairs and faster interfacial electron transfer compared to pure La2Ti2O7 nanosheets and the La2Ti2O7/GR-H nanocomposite. The enhanced photocatalytic H-2 production rate and photo-electrochemistry activity can be ascribed to the intimate interfacial contact and large contact area between the La2Ti2O7 nanosheets and GR, which help to make full use of the electron conductivity of GR for transferring photogenerated electrons, prolonging the lifetime of charge carriers and improving the rate of water splitting to form H-2.