Syntheses of flower and tube-like MoSe2 nanostructures for ultrafast piezocatalytic degradation of organic dyes on cotton fabrics.

The synthesis of few-layered transition metal dichalcogenides (TMDCs) with abundant exposure of the active site, viz., is an important key to achieve excellent dye degradation performance. Here, we have reported synthesis and ultrafast dye degradation performance of flowers-like MoSe2 nanostructure (FMN) with ~230 nm in diameter and its transformation to tube-like MoSe2 microstructure (~1 μm in length) by tuning the solvothermal reaction time. The piezoelectric devices are developed using the FMNs delivers the highest open-circuit voltage of ~ 2.12 V, which is ~21 times higher than that of the developed device with the tube-like MoSe2 microstructure. The piezoelectric property of the synthesized samples has been judiciously utilized further for ultrafast degradation of organic dyes within 60-120 s only under the low-frequency (40 kHz) ultrasonication vibration in the dark. The estimated dye degradation efficiencies of the FMNs-based piezocatalyst are found to be ∼86% and 85% for degradation of Rhodamine B (RhB) and methylene blue (MB) dye within the 60 s, respectively. Also, the FMN has exhibited an excellent piezocatalytic dye degradation capability for RhB-MB dye mixture and dye loaded on a cotton fabric with an efficiency of ~98% (60 s) and 84% (120 s), respectively. The piezocatalytic dye degradation mechanism of FMNs has also been explained theoretically.