Photocatalyst is the core of photocatalysis and directly determines photocatalytic performance. However, low quantum efficiency and low utilization of solar energy are important technical problems in the application of photocatalysis. In this work, a series of polyoxometalates (POMs) [H₃PW₁₂O₄₀] (PW₁₂)-doped titanium dioxide (TiO₂) nanofibers modified with various amount of silver (Ag) nanoparticles (NPs) were prepared by utilizing electrospinning/photoreduction strategy, and were labelled as x wt% Ag/PW₁₂/TiO₂ (abbr. x% Ag/PT, x = 5, 10, and 15, respectively). The as-prepared materials were characterized with a series of techniques and exhibited remarkable catalytic activities for visible-light degradation tetracycline (TC), enrofloxacin (ENR), and methyl orange (MO). Particularly, the 10% Ag/PT catalyst with a specific surface area of 155.09 m²/g and an average aperture of 4.61 nm possessed the optimal photodegradation performance, with efficiencies reaching 78.19% for TC, 93.65% for ENR, and 99.29% for MO, which were significantly higher than those of PW₁₂-free Ag/TiO₂ and PT nanofibers. Additionally, various parameters (the pH of the solution, catalyst usage, and TC concentration) influencing the degradation process were investigated in detail. The optimal conditions are as follows: catalyst usage: 20 mg; TC: 20 mL of 20 ppm; pH = 7. Furthermore, the photodegradation intermediates and pathways were demonstrated by HPLC-MS measurement. We also investigated the toxicity of products generated during TC removal by employing quantitative structure-activity relationship (QSAR) prediction through a toxicity estimation software tool (T.E.S.T. Version 5.1.2.). The mechanism study showed that the doping of PW₁₂ and the modification of Ag NPs on TiO₂ broadened the visible-light absorption, accelerating the effective separation of photogenerated carriers, therefore resulting in an enhanced photocatalytic performance. The research provided some new thoughts for exploiting efficient and durable photocatalysts for environmental remediation.

Developing high−efficiency membrane materials for the rapid removal of organic dyes is crucial but remains a challenge. Polyoxometalates (POMs) clusters with anionic structures are promising candidates for the removal of cationic dyes via electrostatic interactions. However, their shortcomings, such as their solubility and inability to be mass−produced, hinder their application in water pollution treatment. Here, we propose a simple and green strategy utilizing the room temperature stirring method to mass produce nanoscale polyoxometalate−based metal−organic frameworks (POMOFs) with porous rhomboid−shaped dodecahedral and hexagonal prism structures. The products were labeled as POMOF1 (POMOF-PW₁₂) and POMOF2 (POMOF-PMo₁₂). Subsequently, a series of x wt% POMOF1/PAN (x = 0, 3, 5, and 10) nanofiber membranes (NFMs) were prepared using electrospinning technology, where polyacrylonitrile (PAN) acts as a “glue” molecule facilitating the bonding of POMOF1 nanoparticles. The as−prepared samples were comprehensively characterized and exhibited obvious water stability, as well as rapid selective adsorption filtration performance towards cationic dyes. The 5 wt% POMOF1/PAN NFM possessed the highest removal efficiency of 96.7% for RhB, 95.8% for MB, and 86.4% for CV dyes, which realized the selective separation over 95% of positively charged dyes from the mixed solution. The adsorption mechanism was explained using FT−IR, SEM, Zeta potential, and adsorption kinetics model, which proved that separation was determined via electrostatic interaction, hydrogen bonding, and π–π interactions. Moreover, the POMOF1/PAN membrane presented an outstanding recoverable and stable removal rate after four cycles. This study provides a new direction for the systematic design and manufacture of membrane separation materials with outstanding properties for contaminant removal.

Novel strategies for the sensitive and rapid detection of the anthrax biomarker (2,6-pyridinedicarboxylic acid, DPA) are critical for ensuring food safety and preventing the disease. In this study, a novel fluorescent metal-organic framework (MOF) was fabricated via a directly from waste polyethylene terephthalate (PET) plastic. The sensor exhibited excellent pH stability (pH = 2–10), ultrafast response (within 5 s), a low detection limit (0.15 μM), and strong anti-interference performance. Spectroscopic and DFT studies confirmed that the fluorescence enhancement originates from DPA chelation with Tb³⁺, where DPA acts as an efficient energy-transfer antenna. Building on this mechanism, we demonstrated the immediate visual detection of DPA in tap water, tea, and milk using the MOF solution under UV light. Furthermore, quantitative analysis of DPA in milk was performed via a smartphone-based assay, thereby establishing a rapid, accurate, and practical method for on-site detection.