▎ 摘　　要

Alpha iron. trioxide (alpha-Fe2O3) nanoparticles were synthesized by a phase. separated hydrolysis. solvothermal method, and then modified by coupling 3% (mass fraction) graphene, nitrogen. doped graphene and g-C3N4 as the two-dimensional hetero. materials by a simple wet chemical process. Detailed comparative studies of their effects on photocatalytic activities of alpha-Fe2O3 were carried out. The results show that the photocatalytic activities of nano alpha-Fe2O3 for reducing CO2 to CO and for degrading phenol are enhanced after coupling with all two. dimensional hetero-materials. The modification of nitrogen. doped graphene on alpha-Fe2O3 is better than graphene and the modification of g-C3N4 on alpha-Fe2O3 is the best. Based on the measurements of surface photovoltage responses, photoelectrochemical curves, and hydroxyl radical amounts, it is confirmed that the introduction of two-dimensional hetero-materials would promote the photogenerated charge separation and increase the content of the active intermediate (hydroxyl radicals) consequently, leading to the improved photocatalytic activity of nano alpha-Fe2O3.