Hailin Zhu

Gel electrolytes show great potential for suppressing Zn dendrites and side reactions in Zn-ion batteries. However, the trade-off between ionic conductivity and mechanical strength remains a key limitation. To this end, this study introduces acrylamide (AM) and methyl methacrylate (MMA) into a PTFE fibrous membrane to form a three‐dimensional crosslinked AM/MMA hydrogel network via in situ polymerization, yielding a PTFE‐supported gel composite electrolyte [PTFE@P(AM/MMA)]. The amide groups in P(AM/MMA) trap water by hydrogen bonds and facilitate Zn²⁺ desolvation, while the ester groups in MMA enhance hydrophobic aggregation and crosslinking toughness of the polymer chains. Consequently, the PTFE@P(AM/MMA) electrolyte possesses high ionic conductivity (9.13 mS cm⁻¹) and a Zn²⁺ transference number (0.77). The PTFE substrate provides a robust porous framework with a mechanical strength of 16.17 MPa and puncture force of ~19.56 N, effectively inhibiting the growth and penetration of Zn dendrites. As a result, the Zn||Zn symmetric cell achieved 3,800 h of stable cycling at 1 mA cm⁻². The half-cell maintained near‐100% Coulombic efficiency after 2,000 cycles, and the full cell with a KVO cathode retained 88.6% capacity after 1,000 cycles. These results highlight the great potential of the PTFE@P(AM/MMA) gel composite electrolyte for advanced aqueous Zn‐ion batteries, while also extending the application scope of PTFE fibrous membranes.

Zinc ion hybrid supercapacitors (ZHSCs) can function as a promising electrochemical energy storage system because they combine the high power characteristic of supercapacitors with the high energy capacity of zinc-ion batteries. However, Zn dendrite formation severely restricts the cycle life of ZHSCs. It has been demonstrated that separators with high mechanical strength significantly prolong the cycle life of zinc-metal anodes. Herein, a hydrophilic polytetrafluoroethylene (PTFE)-based separator with high mechanical strength was fabricated by introduction of a mixture of sodium dodecyl sulfate (SDS), polyacrylic acid (PAA), and titanium dioxide (TiO₂) nanoparticles into a PTFE fibrous membrane via a simple suction filtration method. The SDS/PAA/TiO₂/PTFE separator with a thickness of approximately 56 μm possessed high tensile strength (stress 81.2 MPa at 17.5% strain), superior to that of glass fiber (GF) separators (stress 0.3 MPa at 1.0% strain), and suppressed dendrite growth. Also, the SDS/PAA/TiO₂/PTFE separator exhibited promising electrolyte affinity, satisfactory electrolyte uptake (348%), high ionic conductivity of up to 15 × 10⁻³ S cm⁻¹ in 2 M ZnSO₄ aqueous electrolyte, and appropriate porosity (55%). As a result, the ZHSCs based on PAA/SDS/TiO₂/PTFE separator exhibited outstanding electrochemical performance with specific capacitance (65 F g⁻¹) and excellent cycling stability (98.03% retention at 8000 cycles). This work provides new perspectives into the design of PTFE-based separators, and will expand the applications of PTFE by the use of a novel composite separator for the rapid charging of safe electrochemical energy storage devices.

Recently, heterogeneous catalysts prepared by two phase metals were commonly used to activate PMS degradation. However, the synergistic effects of Zn and other metals on the activation of PMS were infrequently studied. In this work, novel PVDF@TA-ZIF-67/8 nanofibers were prepared successfully by first mineralization and then in-situ growth. The prepared PTZ70 exhibited a evidently higher photocatalytic activity than PVDF, PTC, PTZ0, PTZ10 and PTZ100 to degradation OFX(96.5%). The effects of the mass ratio of Co and Zn,PMS dosage, coexisting ions and organic solvents on the degradation of OFX were concretely investigated. The radical trapping experiment and mechanism analysis showed that the synergistic effect of Co and Zn played a key role in PMS activation, accelerating the generation of 1O2 and •O2-. Combining the discussion of influencing factors and LC-MS analysis, four OFX degradation pathways were illustrated. In particular, we observed that the degradation OFX of PTZ70 was only slightly reduced by 5.6% after five cycling, indicating the reusability, good stability and high environmental suitability of PTZ70 performance. This study provides a reference for the design of catalysts with controllable heterogeneous metal doping.

At present, the types of pollutants in wastewater are more and more complicated, however, the multifunctional membrane materials are in short supply. To prepare a membrane with both high efficient oil-in-water emulsion separation performance and photocatalytic degradation performance of organic dyes, the bifunctional separation membrane was successfully prepared by electrostatic spinning technology of PVDF/PEMA and in situ deposition of anatase TiO₂ nanoparticles containing Ti³⁺ and oxygen vacancies (O_v). The prepared composite membrane has excellent hydrophilic properties (WCA = 15.65), underwater oleophobic properties (UOCA = 156.69), and photocatalytic performance. These composite membranes have high separation efficiency and outstanding anti-fouling performance, the oil removal efficiency reaches 98.95%, and the flux recovery rate (FRR) reaches 99.19% for soybean oil-in-water emulsion. In addition, the composite membrane has outstanding photocatalytic degradation performance, with 97% and 90.2% degradation of RhB and AG-25 under UV conditions, respectively. Several oil-in-water separation and dye degradation experiments show that the PVDF composite membrane has excellent reuse performance. Based on these results, this study opens new avenues for the preparation of multifunctional reusable membranes for the water treatment field.

The anti-fouling performance of membranes is an important performance in the separation of oil/water. However, the membrane with anti-fouling performance will also have surface scaling phenomenon when it runs for a long time. Therefore, there is still a great demand for stain-resistant membranes with good self-cleaning ability and high flux recovery rate. Based on this, this paper firstly prepared a hydrophilic membrane with carboxyl group and carboxyl ion by blending poly(ethylene-alt-maleic anhydride) (PEMA) and polyvinylidene fluoride (PVDF), and then prepared a self-cleaning composite membrane by in situ mineralization of β-FeOOH particles on the surface of the membrane for efficient oil-in-water emulsion separation. A large number of –COOH/COO⁻ and β-FeOOH particles on the membrane surface make the composite membrane have strong hydrophilic properties (WCA = 20.34°) and underwater superoleophobicity (UOCA = 155.10°). These composite membranes have high separation efficiency (98.8%) and high flux (694.56 L m⁻² h⁻¹ bar⁻¹) for soybean oil-in-water emulsion. Importantly, the as-prepared membrane shows excellent flux recovery rate (over 99.93%) attributed to the robust photo-Fenton catalytic activity of β-FeOOH, and the β-FeOOH is chemically bonded to the as-prepared membrane, which makes the as-prepared membrane have good reusability. This work provides hope for the application of self-cleaning membranes in the construction of anti-fouling membranes for wastewater remediation.

In this work, antibacterial and antifouling properties Polyvinylidene fluoride (PVDF) composite membranes were prepared via nonsolvent-induced phase separation of PVDF and Zn@TiO₂ blending. The Zn@TiO₂ nanoparticle was successfully prepared by the sol-gel method, and then Zn@TiO₂ was used to modify the PVDF membrane to obtain higher water flux and antibacterial and antifouling properties. The PVDF composite membrane was systematically characterized through a series of analysis techniques, such as scanning electron microscopy (SEM) and X-ray diffraction (XRD). In addition, the water contact angle, pure water flux, tensile strength, porosity, antibacterial property and stain resistance of the membrane have been studied. Escherichia coli and Staphylococcus aureus were used to evaluate the antibacterial performance of the membrane, and the BSA was selected as a model organic pollutant to study the antifouling performance of the membrane. Results show that the PVDF composite membranes have excellent antibacterial properties (nearly 100%), high permeability (up to 433.69 L m⁻² h⁻¹) and mechanical strength (enhanced by 26.5%). It can be used for possible complex high-protein wastewater treatment without facing serious biological pollution problems, and has broad application prospects.