Chiral compounds have a huge market demand in the fields of pharmaceuticals, pesticides, and fine chemicals. Enzymatic electrosynthesis can couple enzyme catalysis, possessing high product purity, high efficiency, and mild conditions, with electrochemical regeneration of expensive cofactor nicotinamide adenine dinucleotide (NADH), possessing easy process monitoring and simple operation for efficient chiral synthesis. In this study, hydrophobic covalent organic framework (COF) was synthesized as the immobilized carrier, which not only enhanced the enzyme catalysis through enriching substrate but also enhanced the stability and reuse of the enzyme. Besides, Rh complex was anchored on hydrophilically-modified electrode to promote the regeneration of NADH, where the anchor of Rh complex can effectively avoid the mutual deactivation from the interference between electron mediator and enzyme, and simplify the separation of products. The immobilized enzyme catalysis and the electrochemical cofactor regeneration were coupled to construct an enzymatic electrosynthesis system for the efficient asymmetric reduction to obtain chiral alcohols, with a maximum turnover frequency (TOF) of 101.1 h⁻¹. Furthermore, the relevant parameters of the system were optimized, and the substrate scope was expanded.

Interfacial polymerization is the most preferred method to fabricate nanofiltration and reverse osmosis membranes in both academia and industry, while it is facing the challenge of high performance, especially in flux. Herein, we proposed a method to incorporate the amino-functionalized molybdenum disulfide (MoS₂–N) nanodots (NDs) in interfacial polymerization to tune the membrane structure, especially the water transport path to enhance membrane performance. MoS₂ NDs have characteristics of high surface smoothness and low fluid diffusion resistance. The MoS₂ NDs incorporated thin-film nanocomposite (TFN) membrane can reduce the water friction resistance in membrane matrix, thus accelerating the transmembrane transfer of water molecules. The morphology and properties of the NDs and membranes were characterized. The functionalization degree and concentration of MoS₂–N NDs in the membrane were tuned. At optimum conditions, the MoS₂–N NDs incorporated TFN membrane exhibited a pure water permeance of 24.98 LMH/bar, 2.5-fold that of the control membrane, with a high Cl^-/SO₄^2- selectivity of 119.2 (NaCl and Na₂SO₄) and a good long-term stability.

The highly efficient chemoselectivity, stereoselectivity, and regioselectivity render enzyme catalysis an ideal pathway for the synthesis of various chemicals in broad applications. While the cofactor of an enzyme is necessary but expensive, the conversed state of the cofactor is not beneficial for the positive direction of the reaction. Cofactor regeneration using electrochemical methods has the advantages of simple operation, low cost, easy process monitoring, and easy product separation, and the electrical energy is green and sustainable. Therefore, bioelectrocatalysis has great potential in synthesis by combining electrochemical cofactor regeneration with enzymatic catalysis. In this review, we detail the mechanism of cofactor regeneration and categorize the common electron mediators and enzymes used in cofactor regeneration. The reaction type and the recent progress are summarized in electrochemically coupled enzymatic catalysis. The main challenges of such electroenzymatic catalysis are pointed out and future developments in this field are foreseen.

The hollow spherical covalent organic frameworks (COFs) have a wide application prospect thanks to their special structures. However, the controllable synthesis of uniform and stable hollow COFs is still a challenge. We herein propose a self-templated method for the preparation of hollow COFs through the Ostwald ripening mechanism under ambient conditions, which avoids most disadvantages of the commonly used hard-templating and soft-templating methods. A detailed time-dependent study reveals that the COFs are transformed from initial spheres to hollow spheres because of the inside-out Ostwald ripening process. The obtained hollow spherical COFs have high crystallinity, specific surface area (2,036 m²·g⁻¹), stability, and single-batch yield. Thanks to unique hollow structure, clear through holes, and hydrophobic pore environment of the hollow spherical COFs, the obtained immobilized lipase (BCL@H-COF-OMe) exhibits higher thermostability, polar organic solvent tolerance, and reusability. The BCL@H-COF-OMe also shows higher catalytic performance than the lipase immobilized on non-hollow COF and free lipase in the kinetic resolution of secondary alcohols. This study provides a simple approach for the preparation of hollow spherical COFs, and will promote the valuable research of COFs in the field of biocatalysis.