MoS2@ZnO nano-heterojunctions with enhanced photocatalysis and field emission properties

The molybdenum disulfide (MoS2)@ZnO nano-heterojunctions were successfully fabricated through a facile three-step synthetic process: prefabrication of the ZnO nanoparticles, the synthesis of MoS2 nanoflowers, and the fabrication of MoS2@ZnO heterojunctions, in which ZnO nanoparticles were uniformly self-assembled on the MoS2 nanoflowers by utilizing polyethyleneimine as a binding agent. The photocatalytic activities of the composite samples were evaluated by monitoring the photodegradation of methylene blue (MB). Compared with pure MoS2 nanoflowers, the composites show higher adsorption capability in dark and better photocatalytic efficiency due to the increased specific surface area and improved electron-hole pair separation. After irradiation for 100 min, the remaining MB in solution is about 7.3%. Moreover, the MoS2@ZnO heterojunctions possess enhanced field emission properties with lower turn-on field of 3.08 V μm−1and lower threshold field of 6.9 V μm−1 relative to pure MoS2 with turn-on field of 3.65 V μm−1 and threshold field of 9.03 V μm−1.