Yanan Gao

Efficient removal of 99TcO4– is crucial for environmental protection and the optimal use of nuclear energy; however, existing adsorbents still face significant challenges in achieving excellent stability and high selectivity. In this work, a picolinaldehyde-based covalent organic framework (COF), TABT-COF, was converted into a chemically stable, imidazopyridinium-based, cationic N+-TABT-COF through a postmodification process. The as-synthesized N+-TABT-COF was used as an adsorbent for the selective adsorption of ReO4–, a nonradioactive substitute for radioactive 99TcO4–. Experimental results show that N+-TABT-COF achieves a ReO4– adsorption capacity of 370.6 mg·g–1, rapid adsorption kinetics (removing over 80% of ReO4– within 1 min), and good reusability. Notably, N+-TABT-COF can effectively remove ReO4– with good selectivity even in the presence of large amounts of competing ions. Combined spectral characterizations and theoretical calculations reveal that the removal of ReO4– is primarily driven by an anion-exchange mechanism between the counterion of N+-TABT-COF and ReO4–. This work offers an effective approach for developing high-performance adsorbents for the adsorption and separation of radioactive 99TcO4– in various types of contaminated environmental waters.

Although covalent organic frameworks (COFs) have garnered significant attention as versatile scaffolds in photocatalysis, it is constrained by the sluggish charge‐carrier dissociation inherent to organic semiconductors. Moreover, how subtle changes in atomic topology within an otherwise similar framework translate into macroscopic optoelectronic behavior remains insufficiently understood. Herein, we demonstrate that precise nitrogen‐site isomerism within the framework backbone serves as a critical lever to manipulate exciton dynamics. By synthesizing two regioisomeric vinylene‐linked COFs, PzDA‐TMT‐COF (pyrazine‐based, para‐N) and DzDA‐TMT‐COF (pyridazine‐based, ortho‐N), we reveal that a subtle translocation of nitrogen atoms induces a profound divergence in charge‐separation efficiency. Despite identical chemical compositions and porosities, the para‐configured PzDA‐TMT‐COF delivers a significantly enhanced hydrogen evolution rate of 13.2 mmol g ⁻¹ h ⁻¹ , significantly outperforming its ortho‐analogue. It is elucidated that this “atomic editing” fundamentally reshapes the intramolecular potential landscape: the para‐substitution maximizes donor–acceptor polarization and minimizes exciton binding energy, thereby accelerating the transition from bound excitons to free charge carriers. Our findings establish a rigorous structure–activity relationship, highlighting that rational control over heteroatom placement is a paramount design principle for organic photocatalysts.

The support effect in platinum catalysts plays a decisive role in governing active-site dispersion and electronic structure, with direct implications for liquid organic hydrogen carrier (LOHC) technologies. Herein, we synthesized a series of Pt catalysts supported on TiO2, γ-Al2O3, and a binary TiO2-γ-Al2O3 to stabilize Pt single atoms and systematically evaluated their catalytic performance in the cyclohexane dehydrogenation to benzene and hydrogen. Structural, compositional and morphological analyses revealed that the binary TiO2-γ-Al2O3 support promotes the formation of highly dispersed and electronically modified Pt species, with a strong metal-support interaction (SMSI) arising from interfacial Ti–O–Al bonding. The catalytic performance of Pt/TiO2-γ-Al2O3 catalyst markedly outperformed its single-oxide counterparts, achieving a remarkable hydrogen production rate of 955 mmol/gPt/min at 295 °C and a WHSV of 9.36 h-1, with high benzene selectivity and stability. The superior performance can be attributed to the synergy between atomically dispersed Pt, the bifunctional mixed-oxide support, and SMSI-induced electronic modulation. This work provides valuable insights for the rational design of high-performance Pt catalysts for on-demand hydrogen production from LOHCs.

Aqueous zinc‐iodine (Zn─I ₂ ) batteries are promising candidates for large‐scale energy storage owing to their inherent safety, low cost, and high theoretical capacity. However, their practical application is hindered by the polyiodide shuttle effect, sluggish iodine redox kinetics, and uncontrolled zinc dendrite growth. Herein, we design a functional separator modified with metallophthalocyanine‐based covalent organic frameworks (MPc‐COFs, M═Co, Ni, Cu) to simultaneously regulate iodine electrochemistry and zinc deposition behavior. The optimized Gr@CoPc‐COF@GF separator leverages a synergistic mechanism: atomically dispersed Co active sites strongly adsorb polyiodides to suppress shuttling while accelerating iodine redox kinetics, and the well‐ordered CoPc‐COF nanochannels facilitate uniform Zn ²⁺ flux. As a result, the corresponding Zn─I ₂ battery delivers a high specific capacity of 208.6 mAh g ⁻¹ at 571 mA g ⁻¹ and achieves excellent capacity retention with 96.97% Coulombic efficiency after 48 h of open‐circuit rest. This work presents a rational separator design strategy for high‐performance Zn─I ₂ batteries, highlighting the importance of molecular‐level engineering in advanced energy storage systems.

Developing high‐efficiency adsorbents for the selective capture of thorium from uranium and rare earth elements necessitates integrating multiple critical functions, including strong adsorption ability, exceptional selectivity, and acid‐resistance performance, posing a technically challenging task. Herein, guided by the hard‐soft acid‐base (HSAB) principle, a series of imine‐linked covalent organic frameworks (COFs) functionalized by oxygen‐rich groups is designed and synthesized. The abundance of high‐affinity dual‐active N and O sites on the COF skeleton enables rapid adsorption kinetics and superior Th(IV) uptake. Particularly, TPT‐PA‐COOH and TPT‐PA‐SO ₃ H exhibit record‐breaking saturated adsorption capacity and Th/U separation selectivity, making them the most efficient Th(IV) adsorbent reported to date. Especially, the introduction of –COOH or –SO ₃ H groups renders the 2D COFs highly acid‐resistant, while keeping good Th(IV) adsorption capacity and selectivity even under harsh acidic conditions. These findings provide insight into the coordination mechanism between thorium and functional binding sites, thus advancing applications of COFs in the separation of thorium from radioactive wastewater.

A porphyrin-based covalent organic framework system doped with Fe²⁺ and dihydroartemisinin (DHA) has been developed for enhanced antitumor therapy. This platform enables coordinated generation of reactive oxygen species (ROS) including DHA-derived radicals, Fe²⁺-driven chemodynamic therapy (CDT), and porphyrin-mediated photodynamic therapy (PDT), which collectively amplify oxidative stress and significantly improve therapeutic efficacy.