Chongli Zhong

Manipulating the spin state of charge carriers via the chiral‐induced spin selectivity (CISS) effect enhances charge carrier dynamics and lowers kinetic barriers, thereby advancing the photocatalytic upcycling of plastics into renewable chemicals. Here, a chiral‐ligand‐induced interfacial assembly strategy was developed to construct heterojunctions for waste plastics photoreforming. Enantiopure cysteine grafted onto MOF‐808 directs the uniform growth of a TpPa‐COF shell enabling self‐adaptive lattice matching. The heterojunctions exploit the CISS effect to regulate the spin alignment of photogenerated charge carriers. Spin‐polarized electrons are funneled to Pt single atoms, delivering an H ₂ evolution rate of 1255.74 µmol g ⁻¹ h ⁻¹ . During oxidation of polyethylene terephthalate‐derived ethylene glycol, spin‐polarized holes on Pt clusters favor the parallel spin alignment of *OH intermediates, directing the reaction pathway on chiral catalysts toward C2‐retained glycolic acid (865.96 µmol g ⁻¹ h ⁻¹ ; 90.53% selectivity). In contrast, antiparallel spin alignment on achiral counterparts drives C‐C bond cleavage, yielding the C1 product formic acid. Scalable synthesis, outdoor testing, and techno‐economic analysis demonstrate the practical viability of this approach for solar‐driven waste plastic upcycling.

Two-dimensional (2D) metal–organic framework (MOF) nanosheets possess great potential in gas separation, photocatalysis, and other advanced applications, benefiting from their ultrathin morphology, high specific surface area, and abundant exposed active sites. However, rational synthesis of 2D nanosheets from nonlamellar high-valent metal MOFs remains challenging due to the lack of exploitable weak interlayer interactions. Herein, we report a versatile bottom-up strategy for “low-valent metal-induced lattice expansion–crystalline shear–competitive growth” to address this issue. Taking NaBH4-induced Ti(IV) reduction to Ti(III) as an example, the inherently longer bond length and lower bond energy of Ti(III)–O bonds induce NH2-MIL-125 unit cell expansion, preferential out-of-plane Ti–O bond cleavage, and rapid in-plane lateral competitive growth. This transforms NH2-MIL-125 from 3D particles (∼500 nm diameter, aspect ratio 2:1) to large-area ultrathin 2D nanosheets (∼20 μm lateral size, ∼35 nm thickness, an ultrahigh aspect ratio ∼600:1), the value of which is 35 times higher than the previous record. Notably, this surfactant- and layered-precursor-free approach is extendable to other nonlamellar Ti-MOFs. Extended X-ray absorption fine structure (EXAFS), integrated differential phase contrast STEM (iDPC-STEM), and other techniques verify the 2D structural evolution, oxygen vacancies, and unsaturated Ti sites. Practically, NH2-MIL-125 nanosheet-based MMMs exhibit 4.1-fold higher CO2/CH4 selectivity than their 3D counterparts, and the 2D nanosheets achieve a 3.3-fold higher CO production rate in visible-light CO2 photoreduction. This work breaks the paradigm of 2D MOF synthesis relying on layered structures, establishes an extensible methodology for the 2D transformation of nonlamellar high-valent metal MOFs, and advances their energy and environmental applications.

CH ₄ ‐rich coal‐bed methane (CBM) is often contaminated with N ₂ , but their similar properties make conventional separation energy‐intensive and inefficient. Herein, we report a photocatalytic strategy for selective N ₂ conversion over CH ₄ , achieving simultaneous CBM purification and nitrogen valorization. A Co‐Ni metal‐organic framework (CoNi‐PYZ) features isolated bimetallic sites, where ligand/Co units donate electrons to Ni, establishing spatially separated reduction and oxidation centers. This structural motif drives a photocatalytic cascade nitrogen fixation that N ₂ is first reduced to NH ₃ at the Ni sites; subsequently, the generated NH ₃ outcompetes CH ₄ for the Co sites, leading to its oxidation to NO ₃ ^– . This remarkable selectivity is governed by the high polarity and lone‐pair electron donation of NH ₃ , favoring its adsorption over nonpolar CH ₄ . Notably, the optimal catalyst achieves high activity under mild conditions without sacrificial agents, delivering NH ₄ ⁺ and NO ₃ ^– production rates of 599.8 and 199.8 µmol g ^{− 1} h ^{− 1} , respectively. Mechanism analysis reveals that ligand engineering optimizes the d‐band center to balance adsorption and desorption, thereby minimizing the rate‐determining step barriers for both half‐reactions, consistent with the Sabatier principle. This work provides a reaction‐driven alternative to traditional phase‐separation, establishing a novel paradigm for CBM upgrading coupled with selective N ₂ transformation.

CH ₄ ‐rich coal‐bed methane (CBM) is often contaminated with N ₂ , but their similar properties make conventional separation energy‐intensive and inefficient. Herein, we report a photocatalytic strategy for selective N ₂ conversion over CH ₄ , achieving simultaneous CBM purification and nitrogen valorization. A Co‐Ni metal‐organic framework (CoNi‐PYZ) features isolated bimetallic sites, where ligand/Co units donate electrons to Ni, establishing spatially separated reduction and oxidation centers. This structural motif drives a photocatalytic cascade nitrogen fixation that N ₂ is first reduced to NH ₃ at the Ni sites; subsequently, the generated NH ₃ outcompetes CH ₄ for the Co sites, leading to its oxidation to NO ₃ ^– . This remarkable selectivity is governed by the high polarity and lone‐pair electron donation of NH ₃ , favoring its adsorption over nonpolar CH ₄ . Notably, the optimal catalyst achieves high activity under mild conditions without sacrificial agents, delivering NH ₄ ⁺ and NO ₃ ^– production rates of 599.8 and 199.8 µmol g ^{− 1} h ^{− 1} , respectively. Mechanism analysis reveals that ligand engineering optimizes the d‐band center to balance adsorption and desorption, thereby minimizing the rate‐determining step barriers for both half‐reactions, consistent with the Sabatier principle. This work provides a reaction‐driven alternative to traditional phase‐separation, establishing a novel paradigm for CBM upgrading coupled with selective N ₂ transformation.

The sustainable, green, solvent-free synthesis offers new pathways for constructing high-performance metal-organic frameworks (MOFs) that are challenging to access via conventional solution chemistry. Herein, using this approach, we synthesize a highly stable crystalline chromium-phosphonate MOF, TGU-20, while a different counterpart, TGU-30, was obtained in the solution with the same ligand and Cr³⁺ ion. Interestingly, the three-dimensional electron diffraction technique reveals that TGU-20 adopts a monodeprotonated bidentate phosphonate coordination mode, forming ultranarrow channels densely lined with proton-donating acid P-OH groups. In contrast, TGU-30 features a mixed mono/dideprotonated coordination, resulting in large channels with sparse P-OH sites. As a result, TGU-20 displays exceptional proton conductivity of over 10^-2 S cm^-1 at 100% RH with a very low activation energy of 0.10 eV, reaching record-high room-temperature proton conductivity among phosphonate MOFs and 2 orders of magnitude higher than that of TGU-30. Additionally, both MOFs exhibit high stability in harsh conditions, including highly concentrated strong acid. The solvent-free synthesis not only directly yields a chromium-phosphonate MOF for the first time but also opens a mild and green avenue for selectively tuning metal-ligand coordination in reticular chemistry.

Solvent-free synthesis enhances sulfonate coordination, enabling the first assembly of Cr( iii )-SO ₃ coordination polymers with high stability and proton conductivity and reversing the coordination hierarchy from –SO ₃ ⁻ < –COO ⁻ to –SO ₃ ⁻ > –COO ⁻ .