Hierarchical MoS2 hollow microspheres with high piezoelectric catalytic performance prepared by the soft-template method

Hierarchical porous MoS2 hollow microspheres (MoS2 HMS) assembled from nanosheets were prepared through a simple, one-step hydrothermal process using tetrabutylammonium bromide (TBAB) as a template. The samples were characterized by XRD, SEM, XPS and BET techniques, and a possible formation mechanism for the porous MoS2 HMS prepared by the soft template method was proposed. Degradation of methylene blue (MB) was used as a model reaction to investigate the piezoelectric catalytic performance of the MoS2 HMS, and which was further applied to the piezoelectric catalytic degradation of rhodamine B (RhB), ciprofloxacin (CIP), tetracycline (TC), and oxytetracycline (OTC), respectively. The results showed that MoS2 HMS with a 2H phase could be successfully prepared under conditions of a hydrothermal temperature of 240 °C, a hydrothermal time of 24 h, and a TBAB concentration of 8 g/L. The particle size of the microspheres was between 2 and 4 μm, and the particle size distribution was uniform with a specific surface area of 41.8 m2/g. Under the driving effect of ultrasonic waves, the degradation rates for MB and RhB in 150 s were up to 98.0 % and 86.4 %, respectively, and the degradation rate for CIP in 300 s was 88.9 %, and the rates for TC and OTC in 600 s were 72.9 % and 80.3 %, respectively. The radical trapping experiments showed that hydroxyl radicals (OH) and superoxide radicals (O2–) were the main reactive oxygen species (ROS) for pollutants degradation.