The preparation technology and catalytic mechanism of PVDF/PVP/a-MoSx porous membrane for water flow driven piezoelectric PMS activation

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 498; p. 155584
• Main Authors: Li, Yue, Wang, Conghui, Fan, Minghao, Yu, Xiang, Qin, Gang, Qiu, Lele, Yin, Kai, Wang, Longlu
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.10.2024
• Subjects: Amorphous molybdenum sulfide; Non-solvent induced phase separation; Peroxymonosulfate; Piezoelectric catalysis; Water flow; Piezoelectric catalysis; Non-solvent induced phase separation; Peroxymonosulfate; Water flow; Amorphous molybdenum sulfide
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.155584

The PVDF/PVP/a-MoSx 3 % membrane with finger-like pores was designed by introducing a-MoSx with multiple active sites into the piezoelectric material PVDF. The application of membranes to water flow driven piezoelectric-activated PMS facilitates the production of radicals and nonradicals. The membrane is not affected by anions and pH (3.0–11.0) and can be prepared on a large scale. [Display omitted] •A multifunctional PVDF/PVP/a-MoSx membrane was prepared by NIPS.•Finger pore-like structure exposes more catalyst active sites.•PVDF/PVP/a-MoSx with large dipole moment promote the transfer of the charges.•Piezoelectric catalysis-coupled PMS activation produces more active species.•Common anions and natural water resources even promote TC degradation. Piezoelectric catalysis couples with peroxymonosulfate (PMS) activation technology can efficiently increase the yield of reactive oxygen species (ROS). Herein, a novel flexible polyvinylidene difluoride/polyvinyl pyrrolidone/amorphous molybdenum sulfide (PVDF/PVP/a-MoSx) membrane with finger-like pore structure was prepared by non-solvent induced phase separation (NIPS) method. As a result, a-MoSx nanosheets can be exposed out of the pores to provide multiple active sites. The PVDF/PVP/a-MoSx with large dipole moment can form enhanced polarization field under water flow to accelerate the charges separation and transfer, thereby promoting the breakage of the OO bond of PMS. The mechanism of piezo-photocatalytic activated PMS was confirmed by COMSOL multiphysics simulations, electrochemical experiments, contribution of active species and DFT calculations. Moreover, a self-cycling degradation reactor was proved more effective in generating piezoelectric potential and improving the degradation efficiency, supporting the practical potential of this strategy. This study provides a new platform to develop piezoelectric porous membrane for enhanced PMS activation under low density flow water energy.