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Harnessing the power of symmetry‐protected bound states in the continuum (SP BICs) has become a focal point in scientific exploration, promising many interesting applications in nanophotonics. However, the practical realization of ultrahigh quality (Q) factor quasi‐BICs (QBICs) is hindered by the fabrication imperfections. In this work, an easy approach is proposed to achieve ultrahigh‐Q resonances by strategically breaking symmetry. By introducing precise perturbations within the zero eigenfield region, QBICs with consistently ultrahigh‐Q factors, beyond conventional limitations are achieved. Intriguingly, intentionally disrupting symmetry in the maximum eigenfield region leads to a rapid decline in QBIC's Q‐factors as the asymmetry parameter increases. Leveraging this design strategy, ultrahigh‐Q modes with a high Q‐factor of 36,694 in a silicon photonic crystal slab are experimentally realized. The findings establish a robust and straightforward pathway toward unlocking the full potential of SP BICs, enhancing light‐matter interactions across diverse applications. [ABSTRACT FROM AUTHOR]

In order to improve the air filtration efficiency of polypropylene (PP) melt-blown nonwoven, polyacrylonitrile (PAN)/PP composite fiber membrane was prepared by electrospinning, and the effects of process parameters on its filtration efficiency, air filtration resistance and anti-bacterial performance were studied. Test results showed that filtration efficiency of the composite fiber membrane with both salt and oil particles was significantly improved compared with PP melt-blown nonwoven. The filtration efficiency of salt particles and oil particles could be reached the highest as the spinning solution concentration was 12%, the spinning voltage was 10 kV, and the spinning time was 90 min. When the spinning solution concentration was 10% and the spinning voltage was 10 kV, the anti-bacterial performance of the composite fiber membrane was enhanced with the increase of spinning time. After 90 min of electrostatic spinning, the composite fiber membrane already had a specific anti-bacterial performance. It is considered that the prepared PAN/PP composite fiber membrane has certain advantages as filter elements for breathing protection, such as masks. [ABSTRACT FROM AUTHOR]

The production of abundant free radicals and the effective separation of photo-induced carriers are considered challenging by researchers for the application of photocatalytic technology in the field of wastewater purification and environmental remediation. Herein, we successfully synthesized a novel S-MIL-101(Fe)@CQD composite via multi-step synthetic routes involving a simple solvothermal synthesis method and annealing treatment process to remove both Cr6+ and dyes in wastewater. A series of characterization methods and photocatalytic property tests were performed, proving that the synthesized S-MIL-101(Fe)@CQDs exhibited higher photocatalytic activity than MIL-101(Fe), which is mainly due to the formation of an intramolecular energy level and modulation of the intrinsic electronic properties of the MOF, where the CQDs act as an electron acceptor. We proposed the underlying photocatalytic mechanism through trapping experiments of the active species. Also, we performed several typical pollutant degradation experiments and confirmed the wide applicability of this composite. In summary, this work provides new insight into the construction of modified MOFs for the efficient removal of toxic pollutants from water. [ABSTRACT FROM AUTHOR]

A regenerable MgO-coated magnetic Fe 3 O 4 @SiO 2 (FSM) composite effectively avoided the agglomeration of nano-MgO, which was resoundingly used for efficient and rapid phosphorus removal from aqueous solutions. Based on an initial screening of synthesized FSM with different Mg/citric acid molar ratios in terms of phosphorus adsorption capacity, an FSM composite with a Mg-citric acid molar ratio of 1:1 (FSM-1:1) was determined as the optimal choice. Scanning electron microscope (SEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD) showed that the prepared Fe 3 O 4 was triumphantly loaded and the nano-MgO nanoparticles were evenly distributed on the surface of magnetic mesoporous silica. N 2 adsorption-desorption experiments manifested that FSM-1:1 had a large specific surface area of 124.3 m 2 /g and the pore size distribution calculated based on the BJH model was centered at 9.36 nm. Furthermore, FSM-1:1 not only exhibited fast adsorption kinetics (60 min) but also had a high maximum theoretical adsorption capacity of 223.6 mg P/g, which was superior to all the other Mg-based adsorbents. Remarkably, due to the coating of MgO, FSM-1:1 exhibited ultra-high stability in the pH range of 3-11, a wider range than many other Mg-modified sorbents. Our adsorbents also showed excellent selectivity for phosphate anions even in the presence of various coexisting anions (e. g. NO 3 - , Cl - and SO 4 2- ) with varying ionic strengths (0.01 and 0.1 M), good recyclability, the removal rate of phosphate still reached 89.0% after three cycles. Electrostatic attraction, Lewis acid-base interaction and the ligand exchange between Mg-OH and phosphate anions were responsible for the phosphate adsorption mechanisms., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)