Rui Zhu

Phosphotriesterase (PTE) biodegradation of organophosphorus pesticides (OPs) is an efficient and environmentally friendly method. However, the instability and nonreusability of free PTE become the key factors restricting its practical application. In this study, a novel cross-linked magnetic hybrid nanoflower (CLMNF) was prepared. Molecular dynamics (MD) simulations were performed to further investigate the enhanced catalytic efficiency of the enzymes. The recovery rate of enzyme activity was 298% due to the large specific surface area and metal ion activation effect. More importantly, the immobilization scheme greatly improved the stability and reuse performance of the catalyst and simplified the recovery operation. CLMNFs retained 90.32% relative activity after 5 consecutive cycles and maintained 84.8% relative activity after 30 days at 25 °C. It has a good practical application prospect in the degradation and detection of OPs. Consequently, the immobilized enzyme as a biocatalyst has the characteristics of high efficiency, stability, safety, and easy separation, establishing the key step in a biodetoxification system to control organophosphorus contamination in food and the environment.

The synthesis of 2,5‐diformylfuran (DFF) through photocatalytic oxidation of 5‐hydroxymethylfurfural (HMF) is an attractive approach. In this manuscript, a photocatalytic selective oxidation strategy for HMF was developed, using Ag/Ag ₃ PO ₄ as the photocatalyst and O ₂ as the oxidizing agent. The prepared catalyst was characterized systematically by SEM, XRD, XPS, UV‐Vis, PL spectra, and so on. In contrast to previous photocatalytic oxidation strategies for HMF conversion, this catalytic system could efficiently generate ¹ O ₂ without other reactive oxygen species (ROS) under visible light irradiation. DFF would be obtained with about 90 % selectivity. Moreover, the exclusive formation of ¹ O ₂ was linked to the more positive conduction band potential (+0.90 eV) of Ag/Ag ₃ PO ₄ , confirmed by an array of characterization techniques. Additionally, the stability of the catalyst was assessed through cyclic testing and analyses including XRD, and XPS. Nonetheless, this catalytic system could potentially serve as a robust platform for various selective oxidation reactions in the future, due to its exclusive presence of ¹ O ₂ without the involvement of other ROS.

The effective cleavage of C−O bonds in linkages of lignin was one of the significant strategies promoting lignin valorization. Herein, the strategy of C−O bonds cleavage of lignin using metal triflate as the catalyst was developed. The carboxylic acid or alcohol could be used as the nucleophile to stabilize the reactive intermediates formed during the depolymerization of lignin, and the corresponding ester/ether compounds could be obtained. This catalytic system was suitable for the C−O bond cleavage in α‐O‐4 and β‐O‐4 linkages with excellent efficiency. Additionally, reaction conditions were optimized. The reaction mixture was detected by ¹H NMR, and no other byproducts were found. As for treated lignin samples, the cleavage of C−O bonds in linkages was determined by 2D HSQC NMR, the increased content of the phenol hydroxyl group was proved by FT‐IR, and the reduced molecular weight was investigated by GPC. Furthermore, multiple phenolic compounds were detected by GC‐MS in the reaction mixtures.