▎ 摘　　要

Highly efficient Eu-TiO2/graphene composites were synthesized by a two-step method such as sol-gel and hydrothermal process. The synthesized photocatalysts were characterized by XRD, TEM, XPS, UV vis diffuse reflectance spectroscopy and photoluminescence (PL) spectroscopy. The results confirmed that anatase Eu-TiO2 nanoparticles with average 10 nm sizes were successfully deposited on two-dimensional graphene sheets. The UV visible spectroscopy showed a red shift in the absorption edge of TiO2 due to Eu doping and graphene incorporation. Moreover, effective charge separation in Eu-TiO2/graphene composites was confirmed by PL emission spectroscopy compared to TiO2/graphene, Eu-TiO2 and pure TiO2. The photocatalytic activity for H-2 evolution over prepared composites was studied under visible light irradiation (lambda >= 400 nm). The results demonstrate that photocatalytic performance of the photocatalysts for hydrogen production increases with increasing doping concentration of Eu upto 2 at%. However, further increase in doping content above this optimum level has decreased the performance of photocatalyst. The enhanced photocatalytic performance for H-2 evolution is attributed to extended visible light absorption, suppressed recombination of electron-hole pairs due to synergistic effects of Eu and graphene.