Consequently, the hydrogen evolution rate of the 5 wt% graphene modified TiO2 was 8.6 µmol h -1 , which was 1.9 times more than that of P25 (4.5 µmol h -1 ). Of course, other factors also contributed to TiO2/graphene's increased photocatalytic activity in addition to its bigger surface area. Third, defect sites and oxygen-containing functional groups on carbon materials serve as nucleation sites, facilitating the uniform development and anchoring of nanoparticles. These properties address one of the primary challenges in photocatalysis: the rapid recombination of photogenerated electrons and holes. Carbon materials, due to their high conductivity, can capture photogenerated electrons from the conduction bands (CBs) of semiconductors or the lowest unoccupied molecular orbitals (LUMO)