ACS Nano最新文献

Cesium-formamidinium lead triiodide perovskite quantumdots (Cs_xFA_1–xPbI₃ PQDs) exhibit great potential for next-generationphotovoltaics,but the formamidinium (FA⁺) cations at the surface latticeof PQDs suffer from dissociation from the surface lattice due to weakbinding strength, markedly deteriorating the optoelectronic performanceand stability of PQDs. Herein, 2-(aminomethyl)pyridine (2-PyMA) isscreened out to in situ react with the surface FA⁺ cation,forming the N-(2-methylpyridine)formamidinium (2-MPyFA⁺) cation. The in situ formed 2-MPyFA⁺ cation robustlyanchors on the surface lattice of PQDs as functional ligands, whichsubstantially suppresses the formation of surface lattice vacancies,resulting in PQDs with enhanced optoelectronic performance and stabilitybeing obtained. Additionally, PQDs also exhibit high orientation inPQD solids with enhanced electronic coupling, facilitating chargecarrier transport between adjacent PQDs. Consequently, PQD solar cellsyield an efficiency of up to 18.55%, representing the highest efficiencyfor Cs_xFA_1–xPbI₃ PQD solar cells. This study demonstrates valuableinsights into the chemical design principles of surface ligands withexecutable approaches to realizing high-efficiency solar cells orother emerging optoelectronic devices.

Lithium metal is considered as the ultimate anode forhigh-energy-densitybatteries, yet its practical realization is thwarted by dendrite proliferationand chemomechanical interfacial instability. While epitaxial growthon crystallographically textured substrates provides a template forordered deposition, sustaining this ordered growth under high capacitiesand current densities remains a formidable kinetic challenge. Herein,we overcome this barrier by engineering an elastic (110)-orientedlithium anode (e-Li (110)) comprising a conductive polymer scaffold.The e-Li (110) integrates preferred (110) crystallographic orientationwith a mechanically coupled strain corresponding to the optimized4% tensile-strain condition. Consequently, this strain-engineeringstrategy enables a capacity of 30 mAh cm^–2 and currentdensity of 25 mA cm^–2 before lithium epitaxial breakdown.5.9 Ah Li || LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) pouch cells with a high energy density of 509.8Wh kg^–1 show 90% capacity retention after 140 cycles.In sulfide-based all-solid-state batteries (ASSBs), e-Li (110) anodeenables stable cycling for over 1600 cycles at a rate of 5 C. By highlightingstrain as a critical parameter, our work provides a strategy for mechano-electrochemicalcoupling in lithium metal anodes for high-rate, high-energy-densitybatteries.

Spatial organization underpins efficient multistep catalysisinnature, yet recreating such organization on living cell surfaces usingmild, enzyme-compatible and catalytically functional materials remainschallenging. Here we report an l-cysteine-triggered silkfibroin/lysozyme ultrathin film (SLF) that assembles directly on livingmicrobial cells as a catalytic surface layer. SLF forms continuousnanoscale coatings on Saccharomyces cerevisiae, Gluconobacter oxydans and Escherichia coli Nissle 1917. Spectroscopic and structuralanalyses show that film formation proceeds through electrostatic complexation,restricted conformational rearrangement, increased hydrophobic exposure,β-sheet-rich ordering and network formation, rather than simpledeposition. The coating maintains cell viability, enhances stresstolerance and provides size-selective permeability for small-moleculetransport. SLF also incorporates exogenous enzymes efficiently duringassembly. As a proof of concept, ω-transaminase-integrated SLFon G. oxydans couples host glyceroloxidation with surface transamination, enabling one-pot conversionof glycerol to serinol with a titer of 2.7 g L^–1 within 12 h, up to 37-fold higher than a stepwise process. Thiswork establishes ultrathin protein films as living catalytic interfacesfor single-cell biocatalyst design and cascade biomanufacturing.

Pyrolysishas been widely employed as a pretreatment strategy toremove organic components from spent lithium-ion batteries, whichis traditionally considered to have minimal influence on subsequentmetal recovery. By investigating the synergistic pyrolysis behaviorof organic composites with spent lithium nickel cobalt manganese oxide(NCM) cathode materials, it is found that the carbonaceous residuesformed during pyrolysis can significantly impact the microstructureand interfacial chemistry of the cathode material and substantiallyhinder the lithium migration during subsequent low-temperature roastingrecovery. It is demonstrated that the functional groups released fromorganic matter selectively adsorb on the cathode surface under thermalconditions, altering the thermal decomposition pathways of organiccomponents, including poly(vinylidene fluoride) (PVDF) and the separator,and impeding their complete volatilization. This interfacial interactionbetween PVDF/separator and cathode active materials promotes the activationand release of lattice oxygen, which further interacts with the partiallydecomposed carbonaceous species and forms oxygen-rich carbonaceouscomposites. These migrate into the particle interior and form dense,conformal coatings along the grain boundaries, yielding a physicalbarrier that obstructs lithium diffusion. During sulfur-assisted roastingfor selective lithium extraction from ternary black mass, this interfacialarchitecture significantly suppresses lithium release, reducing extractionefficiencies to below 80%. In this case, enhancing the oxygen partialpressure facilitates complete oxidation of the carbonaceous species,effectively removing interfacial barriers and restoring the lithiumleaching efficiency to 96.88%. This work underscores the criticalinfluence of pyrolytic pretreatment on the efficiency of pyrometallurgicalrecycling and suggests reconsideration of its presumed inertness.

Theperformance of perovskite X-ray detectors is limited by thestability-sensitivity trade-off. Although 2D/3D heterostructures providea promising route, fabricating single-crystalline interfaces withminimal defects remains challenging. Here, we develop a seed-mediatedin situ directional epitaxy strategy to grow large-area, oriented(PEA)₂PbBr₄/MAPbBr₃ heterocrystals(HE-PPB-MPB) with highly sharp interfaces. Soft lattice matching combinedwith a patterned PDMS stamp guides van der Waals epitaxy of a uniform2D layer on 3D perovskite, suppressing interfacial defects and randomnucleation. The heterocrystals show an ultralow trap density of 3.02× 10⁹ cm^–3 and anisotropic chargetransport, achieving a mobility-lifetime product of 8.94 × 10^–3 cm² V^–1 and resistivityof 4.58 × 10⁹ Ω cm along [100]. Configured asan asymmetric p–i–n photodiode, the detector attainsa high sensitivity of 21,654 μC Gy_air^–1 cm^–2 and an ultralow dark-current drift of 2.28× 10^–4 pA cm^–1 s^–1 V^–1─two orders lower than conventional3D devices. It also delivers a low detection limit of 26.7 nGy_air s^–1, withstands 0.408 Gy_air without degradation, and enables high-resolution low-dose X-rayimaging. This work establishes a potentially generalized crystal-growthparadigm for advanced radiation sensing.

Transition metalcomplex oxides exhibit a diverse array of emergentphysical properties engineered through epitaxial strain. However,the interpretation of strain-driven phenomena is often obscured bystructural modifications─particularly under in-plane tension─whichcan trigger unexpected departures from bulk behavior. Here, we reportthe observation of “frozen epitaxial strain” in complexoxide heterostructures, where epitaxial tensile strain induces a unit-cellvolume expansion that remains locked even after complete substraterelease. Using synchrotron X-ray diffraction, we quantify this irreversiblestructural response, demonstrating that the lattice fails to recoverits bulk-like dimensions in the freestanding state. X-ray photoelectronspectroscopy and first-principles calculations reveal that this expansionis stabilized by a high density of tensile strain-promoted oxygenvacancies. These findings establish a fundamental link between epitaxialtension, defect chemistry, and structural “memory,”providing critical design rules for the controlled fabrication offunctional freestanding membranes and strain-engineered oxide electronics.