Yubing Xiong

The formation of cyclic carbonates by coupling CO2 with epoxides offers a practical way of upgrading the surplus CO2 that has accumulated in the atmosphere, and thus helps to mitigate global warming. Because CO2 is intrinsically robust thermodynamically and sluggish kinetically, however, this transformation usually demands harsh conditions. Herein, a family of porous poly(ionic liquid)s denoted bAm-PIL-x (bAm = bis-amide) was constructed by radical copolymerization of an imidazolium-based ionic liquid monomer (tVIm-IL) and a quaternary ammonium-based ionic liquid monomer (tQAm-IL) in the presence of N,N'-methylenebisacrylamide as the cross-linker. These polymers combine a moderate specific surface area, pores spanning several size regimes, and a pronounced affinity for CO2, which makes them well suited to both capturing and converting CO2. Applied to the coupling of CO2 with epoxides under solvent-free, metal-free, and cocatalyst-free conditions, bAm-PIL-2 delivered excellent performance at a mild 80 °C and 1.0 bar. The catalyst was readily regenerated and recycled, and it accepted a wide range of epoxide substrates. Density functional theory (DFT) calculations together with in situ infrared spectroscopy were used to probe how the catalyst, the epoxides, and CO2 interact, and on this basis a plausible reaction mechanism for the cycloaddition is proposed. The present findings offer meaningful guidance for designing highly efficient catalysts for CO2 conversion.

Coordinating proton and electron transport remains a central challenge in photocatalysis, particularly for H₂O₂ synthesis, where two-electron oxygen reduction requires synchronized proton delivery and charge transfer. Here, we report hydroxyl-functionalized three-dimensional covalent organic framework (COF) membranes that regulate proton-coupled electron transfer within ordered nanochannels. Phenolic hydroxyl groups are precisely embedded in the membrane pores as internal proton reservoirs, while the continuous COF framework provides pathways for photogenerated electron transport. By tuning hydroxyl density, the dihydroxylated COF-2OH membrane establishes an optimal proton-management microenvironment, promoting O₂ adsorption, charge separation, superoxide/*OOH intermediate formation, and dynamic proton recycling. Under one-sun irradiation in pure water and ambient air, COF-2OH achieves an H₂O₂ production rate of 21.79 mmol g^{- 1} h^{- 1} without sacrificial agents or cocatalysts, greatly outperforming the corresponding powder catalyst. Mechanistic experiments and simulations reveal that membrane confinement and hydroxyl-mediated proton buffering jointly synchronize proton and electron fluxes during continuous photocatalysis. The free-standing membrane can also be integrated into a tubular Al₂O₃-supported reactor for in situ H₂O₂-driven photo-Fenton degradation of organic pollutants. This work establishes proton-managing COF membranes as programmable reaction interfaces for efficient solar H₂O₂ production and integrated water treatment.

Microplastic (MP) pollution is a global environmental concern, and conventional advanced oxidation processes (AOPs) for MP removal often require harsh conditions.

The development of highly efficient, multifunctional catalysts featuring cooperative active sites is a complex yet vital endeavor. This study introduces an innovative approach through in situ polymerization, where flexible, cross-linked ionic polymers are synthesized within the channels of flexible, porous polymeric porphyrins. This process yields a series of interwoven frameworks endowed with dual catalytic active sites. The uniqueness of these catalysts lies in the synergistic interaction between metalated porphyrins and ionic components, greatly boosting their catalytic efficiency in the cycloaddition of CO2 and epoxides. The bifunctional catalysts not only surpass the individual constituents in performance but also demonstrate a significant superiority over their physical mixture. The structural flexibility and high density of active sites in these catalysts enable synergistic effects, leading to exceptional catalytic performance. This research marks a substantial leap in catalyst design, introducing a novel method for crafting bifunctional catalysts with dual-activation capabilities.

Adsorption is one of the most convenient and efficient techniques for capturing and enriching various molecules. However, current strategies for the absorbent regeneration still face the challenges of labor‐intensive and/or environmentally unfriendly procedures. In this study, a novel nonporous adaptive framework (NAF) was constructed through rigid π‐stacked azobenzene (Azo) bridges and flexible non‐stacked amino joints. The precisely tuned flexibility of this framework enables adaptive and accessible pores, and sensitively photo‐responsive behavior. The results demonstrate that Azo‐NAF exhibits a remarkable iodine adsorption capacity up to 5.8 g/g. Notably, the adsorbed iodine molecules can be readily released by ultraviolet (UV) irradiation, allowing for facile regeneration and reuse of Azo‐NAF. Mechanistic studies reveal that iodine molecules interact more strongly with cis ‐Azo‐NAF than trans ‐Azo‐NAF. Thus, accompanying the UV‐induced transition from cis ‐ to trans ‐configuration of Azo units, the trapped iodine molecules are released from the framework. Moreover, this unique feature of Azo‐NAF enables remote regulation of iodine‐catalyzed organic reactions. Our finding thus provides a new design strategy for dynamic frameworks and establish how their switchable configurations can be harnessed for a tunable adsorption and desorption performance.

Adsorption is one of the most convenient and efficient techniques for capturing and enriching various molecules. However, current strategies for the absorbent regeneration still face the challenges of labor‐intensive and/or environmentally unfriendly procedures. In this study, a novel nonporous adaptive framework (NAF) was constructed through rigid π‐stacked azobenzene (Azo) bridges and flexible non‐stacked amino joints. The precisely tuned flexibility of this framework enables adaptive and accessible pores, and sensitively photo‐responsive behavior. The results demonstrate that Azo‐NAF exhibits a remarkable iodine adsorption capacity up to 5.8 g/g. Notably, the adsorbed iodine molecules can be readily released by ultraviolet (UV) irradiation, allowing for facile regeneration and reuse of Azo‐NAF. Mechanistic studies reveal that iodine molecules interact more strongly with cis ‐Azo‐NAF than trans ‐Azo‐NAF. Thus, accompanying the UV‐induced transition from cis ‐ to trans ‐configuration of Azo units, the trapped iodine molecules are released from the framework. Moreover, this unique feature of Azo‐NAF enables remote regulation of iodine‐catalyzed organic reactions. Our finding thus provides a new design strategy for dynamic frameworks and establish how their switchable configurations can be harnessed for a tunable adsorption and desorption performance.