Preparation of graphene oxide/semiconductor oxide composites by using atomic layer deposition

摘要

TiO2, Al2O3 and ZnO are grown by atomic layer deposition (ALD) at 80 degrees C on graphene oxide (GO), synthesized by the improved Hummers' method. The preparation steps and the products are followed by FTIR, Raman, TG/DTA-MS, SEM-EDX, XRD and TEM-ED. Both Al2O3 and TiO2 grown with ALD are amorphous, while ZnO is crystalline. Through decomposing methylene orange by UV irradiation it is revealed that the GO itself is an active photocatalyst. The photocatalytic activity of the amorphous TiO2, deposited by low temperature ALD, is comparable to the crystalline ZnO layer, which is the best photocatalyst among the studied oxides. Al2O3 used as reference suppresses the photocatalytic performance of the GO by blocking its active surface sites.