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Poly(3,4-ethylenedioxythiophene) (PEDOT) is widely used in several fields because of its excellent conductivity, strong adhesion, easy synthesis, and good flexibility. However, liquid-phase polymerization often encounters vast organic solvents and complex postprocessing, while vapor-phase polymerization suffers from agglomeration of precursors. Interestingly, when an external magnetic field was carried out and adjusted, numerous magnetic particles were assembled into different arrangements, which could effectively overcome particles’ agglomeration. Herein, magnetic-field-induced vapor-phase polymerization has been explored to make nanoscale PEDOT layers decorate porous Fe3O4particles. Tailoring the magnetic field forces can control the PEDOT loading mass together with their doped levels. Then, the absorption performance of electromagnetic waves of PEDOT-decorated porous Fe3O4particles was optimized by changing the PEDOT loadings and doped levels. Results indicate that the minimum reflection loss value can reach −43.4 dB (14.0 GHz) and the maximum effective absorption bandwidth can extend to 6.49 GHz, which is broader than that of similar absorbers. Related electromagnetic parameters reveal that dielectric loss mechanisms mainly include conductive loss from PEDOT layers, interfacial polarizations from Fe3O4–PEDOT and PEDOT–air/paraffin interfaces, dipole polarizations between doped counterpart anions and positive sulfur ions in the PEDOT skeletons, and relaxation loss. Besides, multiple reflections among numerous particles, abundant scatterings in the porous structures, and magnetic loss involving natural resonance, exchange resonance, and eddy current effect also account for the electromagnetic energy attenuation. Magnetic-field-induced vapor-phase polymerization is a novel and effective method for preparing PEDOT-decorated magnetic materials.

Due to poor visible light responsiveness and easy recombination of photo generated carriers, the photocatalytic performance of a single g-C3N4is limited. This article presents a Z-type Cu2SnS3/g-C3N4(CTS/CN) heterojunction photocatalyst prepared by in-situ growth of CTS on the surface of g-C3N4using a simple solvothermal method. Through SEM results, it can be seen that as the content of g-C3N4increases, the nanosheet gaps of flower shaped microspheres on the surface of CTS/CN increase and the size becomes thinner. The UV-vis DRS experiment showed that the introduction of CTS increased the visible light absorption range of CTS/CN composite and improved its visible light absorption ability.Under the synergistic effect of H2O2, the photocatalytic degradation efficiency of CTS/70% CN towards MO reached 99% at 50minutes，At the same time, the degradation rate constants k of methylene blue (MB), ciprofloxacin (CIP) and levofloxacin (LEV) reached 0.06289min-1, 0.02132min-1and 0.02787min-1respectively at 100min.In the synergistic MO system of H2O2for photocatalytic degradation, free radical capture experiments showed that the main active species were h+and • OH. Combined with the band structure of Cu2SnS3and g-C3N4, a Z-type photocatalytic mechanism was proposed. Under visible light, H2O2rapidly captured the photo generated electrons of CTS/CN, promoting the transport of photo generated carriers. This study provides theoretical guidance for the design and construction of Z-type heterojunctions with superior visible light driven photocatalytic performance.

Bifunctional photocatalytic nanofiltration (NF) membranes are becoming increasingly popular because of their ability to separate and degrade azo compounds (azos) in water. However, several serious drawbacks limit their practical implementation. In this study, a polyamide (PA) layer formed by interfacial polymerization on the polyvinylidene fluoride membrane surface and polydopamine (PDA) were combined with BaTiO3/Ti3C2Tx(BT) nanoparticles to prepare photocatalytic BT@PDA (BTPP) membranes, which integrated physical separation and photocatalytic degradation into a single process. By optimizing synthesis conditions, a BTPP membrane with high water permeability (34.0 L·m–2·h–1·bar–1) and Na2SO4rejection rate (94.7%) was produced. The photocatalytic activity of this membrane was examined by studying the photocatalytic degradation efficiency of several azos. After 180 min of irradiation with a 300 W Xe lamp (λ ≥ 420 nm), the degradation rate of methyl orange (MO) reached 95.3%, while the degradation rates of alizarin yellow GG and methyl red were 92.7% and 83.5%, respectively. The photocatalytic performance of the BTPP membranes for azos degradation was verified by studying the charge transfer process and generation of reactive radical species (·OH and·O2–), and possible structures of the main intermediates formed during MO degradation were identified. This work provides new insights into the synthesis and degradation properties of bifunctional photocatalytic NF membranes.