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Using N,N-bis(1-methylheptyl)acetamide (N503) synergized with TBP-NaFeCl4(TFe), a ternary composite extraction membrane known as TFeN-PIM was created. Under optimum membrane phase conditions, the mass transfer properties of TFeN-PIM-Li(Ⅰ) and its Li/Mg selective separation performance by electric field augmentation were examined, and confirmed the mechanism of TFeN-PIM-Li(Ⅰ) electric field enhanced mass transfer. The findings demonstrate a homogeneous distribution of [FeCl4-] in the TFeN-PIM membrane phase and a decrease in the water contact angle as the TFecontent increases. In the TFeN-PIM membrane, the cation binding order of the composite carrier was H+>Li+>Na+>Mg2+, and the mass transfer was carried out at the interface of the two phases of the membrane through the mechanism of "cation exchange-neutralization", in which Li(Ⅰ) was bonded with the carrier in the form of 2N503-LiFeCl4-2TBP, and showed a fixed-site "hopping" mass transfer characteristics under the reinforcement of electric field. The mass transfer process of the TFeN-PIM- Li(Ⅰ) system under electric field enhancement conforms to the first-order kinetic rate equation, and the voltage (5–45 V) is positively correlated with the permeability coefficient PLi(Ⅰ)but decreases the Li/Mg selectivity of TFeN-PIM. The SLi(Ⅰ)/Mg(Ⅱ)of TFeN-PIM was 9.18 at 3 V. After three cycles of 72 h cycling at 40 V, the decrease rate of PLi(Ⅰ)was <7.42 %, which showed good stability.

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.