Bonding of Graphene to ZnO by Low-Temperature and Low-Pressure Treatment and Their Photocatalytic Properties

Nano-ZnO/graphene composites were directly synthesized at 195 degrees C via the thermal reduction of graphene oxide (GO) through low-temperature heat treatment at low pressure by using ZnO nanoparticles and GO powders as raw materials. The prepared composites were characterized through X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, photoluminescence spectroscopy, and UV-vis diffuse reflectance spectroscopy. The samples' ability to degrade methylene blue (MB) was tested under simulated sunlight. Results indicated that after the introduction of GO, ZnO underwent lattice distortion. Nano-ZnO grains were loaded onto graphene, and the interface between ZnO and graphene was well bonded. The addition of GO enhanced the absorbance of the samples. The addition of an appropriate amount of GO reduced the fluorescence intensity of the samples. The synthesized ZnO/graphene composites had good photocatalytic properties. When the GO content of the raw material was 20 mol%, the samples exhibited excellent photocatalytic activity and degraded MB within 30 min.