Xiaojun Wu

A reversible nonmagnetic–altermagnetic transition is achieved in 2D MOFs via proton-transfer tautomerism. It enables a chemically reversible handle for altermagnetism and shows molecular symmetry as a key design axis for reconfigurable altermagnets.

Solar-driven overall water splitting provides a route for converting solar energy into chemical fuels, but its realization in porphyrin-based metal–organic frameworks (PMOFs) is limited by the difficulty of coupling reduction and oxidation chemistry within a single framework. Herein, first-principles calculations reveal a spatial separation of the frontier electronic states in two-dimensional M–Cu PMOFs (M = transition metal): the conduction-band edge is predominantly associated with the Cu2(COO)4 paddle-wheel node, whereas the valence-band edge is mainly localized on the porphyrin linker. Combined with site-resolved reaction thermodynamics, this electronic partitioning predicts spatially distinct regions for the hydrogen evolution reaction and oxygen evolution reaction. Systematic screening of 27 M–Cu PMOFs identifies Rh–Cu PMOF as the only candidate satisfying the adopted thermodynamic criteria for both half-reactions, with an idealized upper-bound solar-to-hydrogen efficiency of 15.31% under the adopted spectral model. Sure independence screening and sparsifying operator (SISSO) analysis further identifies total magnetic moment, electronegativity, group number, and d-electron count as physically interpretable descriptors of property variations within this M–Cu PMOF series. These results highlight cooperative linker-node electronic regulation as a computational design principle for porphyrin-based frameworks with spatially differentiated redox functions.

Quantum organic–inorganic superlattices, constructed by vertically stacking two-dimensional inorganic crystals and organic molecular layers, offer a powerful platform for encoding emergent electronic states through an interfacial design. However, the precise layer engineering of such hybrid architectures, particularly the deterministic control over vertical stacking periodicities, has remained elusive because of the absence of a predictive thermodynamic framework governing the staging effect in hybrid systems. Here, we demonstrate that thermodynamic design, based on the quantitative competition between intercalant chemical potential and host elastic deformation energy, provides a principled route to programmable layer engineering of organic–inorganic superlattices. By precisely modulating the chemical potential of the intercalant, we achieve selective access to stage-1 intercalation (alternating 1-layer (1L) molecule/1L-SnSe2) and stage-2 intercalation (alternating 1L-molecule/2L-SnSe2) configurations with high structural fidelity. Atomic-resolution imaging reveals long-range periodic order across both staging phases, while angle-resolved photoemission spectroscopy reveals that the engineered layer sequence directly governs the interfacial charge transfer and electronic band structure evolution. The resulting superlattices exhibit stacking-dependent carrier densities and programmable superconducting transitions, establishing the layer sequence as a synthetic handle for quantum functionality. This work establishes thermodynamic design as a guiding principle for the rational layer engineering of quantum-hybrid solids.

P2-type layered oxide cathodes feature high median voltage and outstanding cycling stability, but their specific capacity of merely 80 mAh g–1 severely limits practical utility. Conventional P2/O3 biphasic strategies to boost capacity typically sacrifice structural stability or median voltage. In this work, density functional theory calculations identify the thermodynamic phase-ratio boundary for biphasic stability, confirming that limiting sodium-rich O3 phase below 20% suppresses the detrimental O3-P3 transition during cycling. Guided by this, precise transition metal tuning yields an optimal atomically intermixed P2/O3-93 cathode (Na3/4Ni1/3Fe1/12Mn7/12O2). It exhibits pronounced zero-strain behavior, with volume change reduced from 3.7% (O3-type reference) to <1%. It maintains a 3.3 V median voltage, raises capacity by 40% to 112 mAh g–1, and achieves 93% retention after 500 cycles at 1 C. Furthermore, it enables 300 stable cycles in all-solid-state sodium-ion batteries at 30 MPa, offering a viable route for high-performance layered oxide cathodes.

The selectivity of electrochemical CO reduction (CORR) on Cu‐based catalysts is critically governed by dynamic surface reconstruction and the resulting interfacial adsorbates. However, how reconstruction‐derived surface species cooperatively dictate the acetate pathway remains poorly understood. Here, we employ a Cu ₂ O/Cu heterostructure as a precursor model catalyst that generate a surface enriched in adsorbed OH species (OH _ad ) upon its reconstruction into metallic Cu. Operando spectroscopy characterizations clearly reveal that surface‐enriched OH _ad synergistically strengthens the adsorption and activation of active low‐frequency‐band *CO intermediates and steers C─C coupling toward acetate over ethanol/ethylene through OH _ad ‐CO _ad synergistic interaction, as further corroborated by our first‐principles density functional theory (DFT) calculations. The reconstructed catalyst achieves an acetate Faradaic efficiency of ∼73.7% (79.5% of all C ₂₊ product), delivers a peak partial current density of 298.9 mA cm ⁻² , and maintains stable catalytic operation over 120 h of continuous electrolysis. This work establishes a fundamental operando mechanistic framework linking reconstruction‐derived OH _ad enrichment to selective CO‐to‐acetate electroconversion, and provides guiding principles for rational interfacial engineering of Cu‐based catalysts toward targeted C ₂₊ product selectivity in renewable electricity‐driven CORR.

The electrochemical performances of MXenes (transition metal carbides/nitrides) are critically governed by their surface terminations, yet the role of halogen electronegativity in modulating capacitive behavior remains underexplored. Here, we demonstrate through integrated density functional theory calculations and experimental validation that tailored halogen terminations (F, Cl, Br, I) on Mo2CTx MXenes directly regulate their electric double-layer capacitance. Computational analysis reveals that lower electronegativity terminations reduce electrostatic shielding, thinning the double-layer interface and enhancing charge storage, yielding a capacitance hierarchy: Mo2CFx (9.23 μF/cm2) < Mo2CClx (10.10 μF/cm2) < Mo2CBrx (11.30 μF/cm2) < Mo2CIx (12.96 μF/cm2). Experimentally, solvothermal halogen substitution (HCl/HBr/HI) produces termination-specific Mo2CTx with retained crystallinity and controlled surface chemistry. Electrochemical measurements in 1 M H2SO4 confirm that I-terminated Mo2CTx achieves a specific capacitance of 539.3 F/g at 1 A/g, 2.16 times higher than F-terminated counterparts, with exception rate retention (> 30% at 100 mV/s). This performance stems from I-termination’s dual role, enlarging interlayer spacing for enhanced ion accessibility and increasing surface electron density on Mo atoms, as evidenced by differential charge density analysis. These findings provide a rational design strategy for MXene-based supercapacitors through precise surface termination control, bridging atomic-scale insights to macroscopic energy storage applications.

Li‐rich Mn‐based layered oxides (LRMOs) are essential cathode materials for higher energy densities in batteries. Nevertheless, the release of reactive oxygen species (ROS) at high voltages, accompanied by the migration of surface oxygen vacancies and transition metal ions, results in continuous electrolyte decomposition, irreversible phase transition, and nanovoids formation within bulk materials. These processes significantly shorten cycle life of batteries and limit practical applications. Herein, inspired by biological properties of taurine (TA) in scavenging ROS, we propose a straightforward cathode additive strategy by employing TA to effectively interact with ROS, thereby generating a reversible TA/peroxotaurine redox couple. This innovative mechanism enables efficient recycling of ROS, which in turn inhibits continuous electrolyte decomposition, O ₂ release, and nanovoid formation. Furthermore, the derived high‐quality cathode electrolyte interphase layer, which is rich in inorganic components and thinner in structure, stabilizes the layered structure while ensuring efficient Li ⁺ transport kinetics. Consequently, the modified LRMO demonstrates an exceptional initial Coulombic efficiency of 89% (vs. 81% for LRMO), and a splendid capacity retention of 92% at 1C after 400 cycles (vs. 68% for LRMO). Additionally, the pouch cell paired with graphite anodes exhibits superior capacity retention of 78% after 1000 ultra‐long cycles at 1/3C.

Hybrid sequential deposition (HSD) remains a practical pathway for the scalable fabrication of perovskite photovoltaics, though it is frequently constrained by the formation of dense evaporated precursor frameworks and the associated kinetic limitations of the subsequent solid interdiffusion. These constraints often manifest as incomplete conversion and vertical inhomogeneity in the resulting perovskite film. Herein, we report a transient vapor-deposited mediator (TVM) strategy that translates the principles of liquid-phase mediator engineering to a vapor-phase process. By incorporating Pb(SCN)2 during the coevaporation of inorganic precursors, the resulting framework exhibits modified porosity that facilitates the infiltration of organic salts and lowers the activation energy for the solid-state δ-to-α phase transition. The elimination of the mediator under ambient humidity is accompanied by the egress of FASCN-related volatile species, promoting more complete and uniform conversion through the full film thickness with reduced residual PbI2 and lower trap density. This TVM process enables solar cells’ power-conversion efficiency to increase from 22.3% to 25.2% and yields enhanced operational robustness, retaining 91% of initial performance after 1200 h of thermal aging at 85 °C and 95% after 1600 h of continuous maximum power point tracking under illumination.

Fully compensated ferrimagnets (fFiMs), which combine vanishing macroscopic magnetization with spin-split electronic states, are attractive for stray-field-free spintronics. However, achieving exact moment cancellation typically requires fine control over inequivalent magnetic sublattices, making the rational design of fFiMs a fundamental challenge. Here, we propose a general design strategy for two-dimensional (2D) fFiMs by integrating redox-active noninnocent ligands (NILs) into metal–organic frameworks (MOFs). First-principles calculations demonstrate that fractional metal-to-ligand charge transfer converts NILs from closed-shell linkers into a spin-bearing ligand sublattice that aligns antiparallel to the metal centers, enabling stoichiometric moment compensation. We validated this concept in a family of trigonal 2D chromium MOFs. While the prototype Cr(BTT)2 confirms fully compensated ferrimagnetism, it exhibits intrinsic thermal instability. The modular nature of the NIL strategy allows for chemical refinement, and ligand fluorination (Cr(F-BTT)2) or heavy-chalcogen substitution (Cr(BSeT)2) stabilizes the 2D lattice without disrupting the fFiM ground state. The chemically optimized Cr(F-BTT)2 retains fully compensated ferrimagnetism and exhibits a near-Fermi quasi-Dirac-like band feature with an estimated magnetic transition temperature of 132 K. Extended studies of nitrogen- and phosphorus-based ligands further support the generality and boundary of this approach. These findings establish NIL-directed charge transfer as a chemically programmable handle for engineering 2D-compensated magnets.

Altermagnets are symmetry-defined magnetic phases that combine momentum-dependent spin splitting with zero net magnetization, offering promising opportunities for spintronics. However, their realization is strongly constrained by rigorous symmetry requirements. Exploiting the shared antiparallel magnetic order and vanishing net magnetization between antiferromagnets and altermagnets, we propose a general chemically driven strategy based on asymmetric ligand modification to transform pristine two-dimensional antiferromagnetic metal-organic frameworks into altermagnetic candidates. Using chromium phthalocyanine (CrPc) as a proof-of-concept model, we show that asymmetric modification lowers the local site symmetry at magnetic Cr centers and generates momentum-dependent spin splitting and anisotropic spin densities, as revealed by first-principles calculations. Oxygen-modified CrPc derivatives further illustrate the chemical tunability of this symmetry-control principle. Our work expands the design space of organic altermagnetic candidates and establishes a chemically grounded route for engineering symmetry-governed magnetic functionality in reticular materials.