Synthesis of hydrophobic MoS2 micro-nanoparticles and their photocatalytic performance research

The flower-like micro-nano-MoS2 was synthesized with aging at 220 degrees C for 16 h by an oil-water interface method. By various characterizations, the results showed that the reaction temperature played a great role in the crystal formation of MoS2, while the reaction time affected the size of the particles. Additionally, it was found that by adding different types of surfactants, along with the altered hydrophobicity, the obtained MoS2 micro-nanoparticles exhibited different morphologies, such as flower-like micro-nanospheres, flower-like micro-nanorods, micro-nanorods, and micro-nanosheets. Meantime, in a series of photodegradation experiments on rhodamine B (RhB) and methylene blue (MB) under a fluorescent light (36 W) in the presence of H2O2, the flower-like MoS2 micro-nanospheres displayed better photocatalytic performance than the flower-like micro-nanorods and micro-nanorods with the same specific area. This is probably related to their own petal structure, preventing from coagulation and resulting in the more stable fixedness of dye molecules on the surfaces, in comparison to that of the micro-nanorods. These results are seldom reported and particularly of great significance in applications of micro- and nanoparticles with different shapes. Especially, the pH of environments greatly influenced on the photocatalytic reaction; the most effective photodegradation on RhB was at pH 6.0 while that for MB was at pH >= 9.0. It is mainly due to their different molecular structures and the difference in electric charge between the two dyes at different pH. Given its high efficiency for degrading RhB and MB dyes, the synthesized MoS2 micro-nanoparticles revealed to be a promising photocatalyst to deal with contaminated water and some other relative fields.