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

Highlights: • The first-ever demonstration in the PDMS embedded with the WS2 nanoflowers for the degradation of organic dye in dark environment. • The degradation ratio of the PDMS/WS2 NFs brick reach ~ 99%. • After ten reuse cycles, the decomposition ratio of color lost still retained ~ 90% of the initial value. • The WS2 NFs reaches more than 99.99% to against the Escherichia coli under ultrasonic condition. 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 (${\mathrm{OH}}^{\bullet }$) 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.