Organic-inorganic PVDF/Zn_0.5Cd_0.5S/Ti-NT photocatalytic membrane with synergistic effect of heterojunction and its derived multi-element excitation NO purification

Nitrogen oxides (NO_x), predominantly existing as NO and NO₂ in trace amounts in the atmosphere, pose a severe threat to air quality. To tackle this challenge, solar-powered degradation of NO_x emerges as a promising approach. Herein, we report the development of an innovative organic–inorganic PVDF/Zn_0.5Cd_0.5S/Ti-NT photocatalytic membrane that harnesses the synergistic effect of a heterojunction structure and multi-element excitation. The membrane is fabricated by integrating ferroelectric polyvinylidene fluoride (PVDF) with a highly functional Zn_0.5Cd_0.5S/Ti-NT composite, synthesized via an in-situ growth method from one-dimensional titanate nanotubes H₂Ti₃O₇(Ti-NT). Notably, the PVDF/ZT_60%(PVDF/Zn_0.5Cd_0.5S/Ti-NT_60%) composite film exhibits an optimal NO_x degradation rate of 80.08 %, significantly outperforming Ti-NT/PVDF (0.85 %) and Zn_0.5Cd_0.5S/PVDF (23.5 %). Additionally, the membrane boasts enhanced mechanical properties, with the PVDF/ZT_60% composite film displaying a tensile strength of 2.16 MPa, superior to PVDF/ZT_70% (0.63 MPa). Experimental and theoretical investigations confirm the formation of an efficient heterojunction between Zn_0.5Cd_0.5S and Ti-NT, facilitating the separation of photogenerated electrons and holes, thereby amplifying photocatalytic activity. Density functional theory (DFT) analysis reveals a unique electron transfer phenomenon from Ti-NT (0 1 0) to Zn_0.5Cd_0.5S (1 0 0), modulating the density of states in the conduction band and enhancing the material's oxidation potential. Remarkably, the composite film catalyst demonstrates remarkable stability, retaining 97.40 % of its initial photocatalytic activity after five consecutive cycles. This work introduces a novel paradigm and strategy for efficiently eliminating NO_x pollutants through the irradiation of photocatalytic membranes, leveraging the unique properties of organic–inorganic hybrids and multi-element excitation. Copyright © 2024 Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.