High efficient degradation of dye molecules by PDMS embedded abundant single-layer tungsten disulfide and their antibacterial performance

This work, we achieved the first-ever demonstration in the polydimethylsiloxane embedded with the abundant single-layer tungsten disulfide (WS2) nanoflowers (PDMS/WS2 NFs) for the degradation of organic dye (Rhodamine B, RB) in dark environment. The degradation ratio of the PDMS/WS2 NFs brick reached ~ 99% and achieved ten cycling test where each cycle took 90 min for the decomposition of the dye molecules. The rate constant of the PDMS embedded WS2 NFs was 0.13 (ppms−1), with the highest degradation rate of ~ 6624 ppm L mole −1 s−1. This is the fastest degradation rate using the PDMS embedded with the abundant single-layer WS2 NFs. We further demonstrated the antibacterial properties of single and few-layers WS2 NFs reaches more than 99.99% to against the Escherichia coli (E. coli) under ultrasonic condition. The piezoresponse force microscopy (PFM) and tunneling atomic force microscopy (TUNA) unveil the dramatically piezopotential of the WS2 NFs. The piezopotential was created around the WS2 NFs to generate the reactive oxygen species (ROS) in the water mediator. The electron paramagnetic resonance (EPR) spectra further evidenced that the generation of reactive oxygen species. O2- and hydroxyl (OH∙) radicals under the mechanical strain, were responsible for decomposing the Rh-B dye molecules and the E. coli bacteria in the dark. The PDMS/MoS2 NFs brick was highly repeatable for efficient decomposition of the organic dyes, which further evidenced that by utilizing piezo-catalytic technologies in the absence of light could be an effective solution for converting mechanical energy into usable chemical energy for the degradation of pollutants.