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The hydroxyl-functionalized atomic-thin bismuth subcarbonate in situ transformed from bismuth hydroxide nanotubes enables highly efficient and durable carbon dioxide electroreduction into formate. The unique OH-decoration facilitates active hydrogen supply in near-neutral electrolytes by enhanced water dissociation and strengthened the adsorption of the critical oxygenated intermediate with highly localized surface electron configuration.

Renewable electricity-driven CO2 electroreduction provides a promising route toward carbon neutrality and sustainable chemical production. Nevertheless, the viability of this route faces constraints of catalytic efficiency and durability in near-neutral electrolytes at industrial-scale current densities, mechanistically originating from unfavorable accommodation of *H species from water dissociation. Herein, a new strategy is reported to accelerate water dissociation by the rich surface hydroxyl on bismuth subcarbonate nanosheets in situ electrochemical transformed from bismuth hydroxide nanotube precursors. This catalyst enables the electrosynthesis of formate at current densities up to 1000 mA cm−2 with >96% faradaic efficiencies in flow cells, and a 200 h durable membrane electrode assembly in a dilute near-neutral environment. Combined kinetic studies, in situ characterizations, and theoretical calculations reveal that the atomic thickness strengthens the hydroxyl adsorption, and with a highly localized electron configuration, the hydroxyl-functionalized surface is more affinitive to oxygenated species, thus lowering the barrier for water dissociation and the crucial hydrogenation step in the proton-coupled electron transfer from *OCHO to *HCOOH.

Chiral MnO2 supraparticles as renal-clearance biosensors for dual-mode in vivo detection of metalloproteinase-9 in early cancer diagnosis via circular dichroism (CD) and magnetic resonance imaging (MRI).

In this study, polypeptide TGGGPLGVARGKGGC-induced chiral manganese dioxide supraparticles (MnO2 SPs) are prepared for sensitive quantification of matrix metalloproteinase-9 (MMP-9) in vitro and in vivo. The results show that L-type manganese dioxide supraparticles (L-MnO2 SPs) exhibited twice the affinity for the cancer cell membrane receptor CD47 (cluster of differentiation, integrin-associated protein) than D-type manganese dioxide supraparticles (D-MnO2 SPs) to accumulate at the tumor site after surface modification of the internalizing arginine-glycine-aspartic acid (iRGD) ligand, specifically reacting with the MMP-9, disassembling into ultrasmall nanoparticles (NPs), and efficiently underwent renal clearance. Furthermore, L-MnO2 facilitates the quantification of MMP-9 in mouse tumor xenografts, as demonstrated by circular dichroism (CD) and magnetic resonance imaging (MRI) within 2 h. A strong linear relationship is observed between MMP-9 concentration and both CD and MRI intensity, ranging from 0.01 to 10 ng mL−1. The corresponding limits of detection (LOD) are 0.0054 ng mL−1 for CD and 0.0062 ng mL−1 for MRI, respectively. hese SPs provide a new approach for exploring chiral advanced biosensors for early diagnosis of cancer.

HfRhGe, a promising noncentrosymmetric material for topological superconductivity, exhibits time-reversal symmetry (TRS)-protected Weyl topology in its normal state, featuring disconnected Fermi sheets and multiple surface Fermi arcs. It enters a superconducting phase at low temperatures with a TRS-breaking ground state, evidenced by muon-spin rotation and relaxation (µSR) measurements, detecting a spontaneous magnetic field offering potential applications in quantum electronics.

Weyl semimetals are a novel class of topological materials with unique electronic structures and distinct properties. HfRhGe stands out as a noncentrosymmetric Weyl semimetal with unconventional superconducting characteristics. Using muon-spin rotation and relaxation (µSR) spectroscopy and thermodynamic measurements, a fully gapped superconducting state is identified in HfRhGe that breaks time-reversal symmetry at the superconducting transition. This breaking can trigger a topological phase transition, as time-reversal symmetry protects the normal-state Weyl topology characterized by comprehensive first-principles calculations. Ginzburg-Landau analysis suggests an unconventional loop supercurrent superconducting state realized in HfRhGe. The presence of multiple Weyl points near the Fermi level and surface Fermi arcs dispersing across the Fermi level further support HfRhGe as a promising platform for topological superconductivity. Additionally, its noncentrosymmetric nature with time-reversal symmetry breaking superconducting state suggests that it can exhibit an intrinsic superconducting diode effect, offering novel optical and transport properties, with potential applications in dissipationless quantum electronics.

A novel all-solid-state oxide-ion synaptic transistor is developed, based on a Bi2V0.9Cu0.1O5.35 oxide-ion conductor electrolyte and La0.5Sr0.5FeO3-δ variable-resistance electrodes (channel, gate). This synaptic transistor efficiently operates at temperatures compatible with conventional electronics, exhibiting key synaptic behaviors with low energy consumption and high endurance. Integrated into an artificial neural network simulation, it achieved 96% accuracy in handwritten digit recognition, demonstrating significant potential for neuromorphic computing applications.

Neuromorphic hardware facilitates rapid and energy-efficient training and operation of neural network models for artificial intelligence. However, existing analog in-memory computing devices, like memristors, continue to face significant challenges that impede their commercialization. These challenges include high variability due to their stochastic nature. Microfabricated electrochemical synapses offer a promising approach by functioning as an analog programmable resistor based on deterministic ion-insertion mechanisms. Here, an all-solid-state oxide-ion synaptic transistor is developed, employing Bi2V0.9Cu0.1O5.35 as a superior oxide-ion conductor electrolyte and La0.5Sr0.5FeO3-δ as a variable-resistance channel able to efficiently operate at temperatures compatible with conventional electronics. This transistor exhibits essential synaptic behaviors such as long- and short-term potentiation, paired-pulse facilitation, and post-tetanic potentiation, mimicking fundamental properties of biological neural networks. Key criteria for efficient neuromorphic computing are satisfied, including excellent linear and symmetric synaptic plasticity, low energy consumption per programming pulse, and high endurance with minimal cycle-to-cycle variation. Integrated into an artificial neural network (ANN) simulation for handwritten digit recognition, the presented synaptic transistor achieved a 96% accuracy on the Modified National Institute of Standards and Technology (MNIST) dataset, illustrating the effective implementation of the device in ANNs. These findings demonstrate the potential of oxide-ion based synaptic transistors for effective implementation in analog neuromorphic computing based on iontronics.

3D-printed biomaterials equipped with an “outer AND inner” logic gate are developed by integrating porous piezoelectric sonosensitizers with bioactive glass scaffolds. Ultrasound, acting as the “outer” input signal, can generate reactive oxygen species, and bioactive drugs loaded in sonosensitizers serve as the “inner” input signal to implement epigenetic demethylation regulation. Combining the AND logic-triggered effects, cancer-specific PANoptosis activation is achieved to boost antitumor immune response. Thus, the biomaterial platform enables enhanced sono-piezoelectric immunotherapy for osteosarcoma, along with related antibacterial effects and bone defect repair.

The precise manipulation of PANoptosis, a newly defined cell death pathway encompassing pyroptosis, apoptosis, and necroptosis, is highly desired to achieve safer cancer immunotherapy with tumor-specific inflammatory responses and minimal side effects. Nonetheless, this objective remains a formidable challenge. Herein, an “AND” logic-gated strategy for accurately localized PANoptosis activation, utilizing composite 3D-printed bioactive glasses scaffolds integrated with epigenetic regulator-loaded porous piezoelectric SrTiO3 nanoparticles is proposed. The “logic-gated” strategy is co-programmed by an “outer” input signal of exogenous ultrasound irradiation to produce reactive oxygen species and an “inner” input signal of acid tumor microenvironment to ensure the epigenetic demethylation regulation, guaranteeing the tumor-specific PANoptosis. Specifically, immunogenic PANoptosis triggers dendritic cell maturation and cytotoxic T cell activation, amplifying antitumor immune responses and significantly suppressing osteosarcoma growth, with a suppression rate of ≈73.47 ± 5.2%. In addition, the well-known bioactivities of Sr-doped scaffolds expedite osteogenic differentiation and reinforce bone regeneration. Therefore, this work provides a paradigm of logic-gated sono-piezoelectric biomaterial platform with concurrently exogenous/endogenous activated PANoptosis for controlled sono-immunotherapy of osteosarcoma, and related bone defects repair.

In situ conversion of proton-rich shell to sub-nano F-&P-maskant, which protects the single-crystal Ni-rich cathode from the attack of electrolyte in the long-term cycling and enables superhigh capacity retention of 83% after 800 cycles.

Single-crystal high-nickel oxide with an integral structure can prevent intergranular cracks and the associated detrimental reactions. Yet, its low surface-to-volume ratio makes surficial degradation a more critical factor in electrochemical performance. Herein, artificial proton-rich (ammonium bicarbonate) shell is successfully introduced on the nickel-rich LiNi0.92Co0.06Mn0.02O2 single crystals for in situ electrochemically conversing into inorganic maskant to enhance stability of cathode. The process is that the surficial enriched proton, once released from the ammonium bicarbonate shell (proton reservoir) during 1st charge, is immediately captured by LiPF6, in situ electrochemically conversing to LiF and Li3PO4 sub-nano particle dense maskant (sub-nano F-&P-maskant). The in situ formed compact nano F-&P-maskant significantly resists the cathode against electrolyte attack and improves the surface stability of particles during long-term cycling. Consequently, this surface modification enables 95% capacity retention after 100 cycles at a high voltage of 4.5 V in the half cell and 83% capacity retention after 800 cycles in the full cell. This work demonstrates a strategy for reconstructing the protective layer using the rational design of surficial enriched proton shells for advanced lithium batteries.

A multidirectional sliding ferroelectricity in γ-InSe with a tunable bulk photovoltaic effect due to the existence of multiple polarization states is reported. The multidirectional sliding ferroelectricity is predicted by the theoretical calculations and multiple domain walls are observed experimentally. The multidirectional sliding ferroelectric polarization paves the path to explore novel optoelectronic applications like real-time imaging and neuromorphic computing.

Through the stacking technique of 2D materials, the interfacial polarization can be switched by an interlayer sliding, known as sliding ferroelectricity, which is advantageous in ultra-thin thickness, high switching speed, and high fatigue resistance. However, uncovering the relationship between the sliding path and the polarization state in rhombohedral-stacked materials remains a challenge, which is the key to 2D sliding ferroelectricity. Here, layer-dependent multidirectional sliding ferroelectricity in rhombohedral-stacked InSe (γ-InSe) is reported via dual-frequency resonance tracking piezoresponse force microscopy and conductive atomic force microscopy. The graphene/γ-InSe/graphene tunneling device exhibits a tunable bulk photovoltaic effect with a photovoltaic current density of ≈15 mA cm−2 due to multiple polarization states. The generation of dome-like domain walls is observed experimentally, which is attributed to the multidirectional sliding-induced domains based on the theoretical calculations. Furthermore, the ferroelectric polarization in γ-InSe ensures that the tunneling device has a high photo responsivity of ≈255 A W−1 and a fast response time for real-time imaging. The work not only provides insights into the multidirectional sliding ferroelectricity of rhombohedral-stacked 2D materials but also highlights their potential for tunable photovoltaics and imaging applications.

A novel atomically dispersed catalyst (Co─Se/Co/NC) with the coexistence of Co single-atom sites and Co─Se dual-atom sites, exhibits outstanding ORR activity and stability. The introduction of Se single atoms and the synergistic effect of Co single-atom and Co─Se dual atom can modulate the d-band center of metal sites and promote the desorption of *OH, thereby significantly accelerating the ORR process.

Atomically dispersed transition metal (ADTM) catalysts are widely implemented in energy conversion reactions, while the similar properties of TMs make it difficult to continuously improve the activity of ADTMs via tuning the composition of metals. Introducing nonmetal sites into ADTMs may help to effectively modulate the electronic structure of metals and significantly improve the activity. However, it is difficult to achieve the co-existence of ADTMs with nonmetal atoms and clarify their synergistic effect on the catalytic mechanism. Therefore, elucidating the active sites within atomically dispersed metal-nonmetal materials and unveiling catalytic mechanism is highly important. Herein, a novel hybrid catalyst, with coexistence of Co single-atoms and Co─Se dual-atom sites (Co─Se/Co/NC), is successfully synthesized and exhibits remarkable performance for oxygen reduction reaction (ORR). Theoretical results demonstrate that the Se sites can effectively modulate the charge redistribution at Co active sites. Furthermore, the synergistic effect between Co single-atom sites and Co─Se dual-atom sites can further adjust the d-band center, optimize the adsorption/desorption behavior of intermediates, and finally accelerate the ORR kinetics. This work has clearly clarified the reaction mechanism and shows the great potential of atomically dispersed metal-nonmetal nanomaterials for energy conversion and storage applications.

Developing sufficiently effective bifunctional electrodes for low-voltage hydrogen production at industrial-grade current density is highly significant but challenging. This work innovatively engineers high-entropy alloy nanoflower array electrodes with abundant high-activity sites and optimizable reaction pathways, and achieves unprecedented performance for two-electrode hydrazine oxidation-assisted hydrogen production at industrial-grade current densities.

Developing sufficiently effective non-precious metal catalysts for large-current-density hydrogen production is highly significant but challenging, especially in low-voltage hydrogen production systems. Here, we innovatively report high-entropy alloy nanoflower array (HEANFA) electrodes with optimizable reaction pathways for hydrazine oxidation-assisted hydrogen production at industrial-grade current densities. Atomic-resolution structural analyses confirm the single-phase solid-solution structure of HEANFA. The HEANFA electrodes exhibit the top-level electrocatalytic performance for both the alkaline hydrogen evolution reaction (HER) and hydrazine oxidation reaction (HzOR). Furthermore, the hydrazine oxidation-assisted splitting (OHzS) system assembled with HEANFA as both anode and cathode exhibits a record-breaking performance for hydrogen production. It achieves ultralow working voltages of 0.003, 0.081, 0.260, 0.376, and 0.646 V for current densities of 10, 100, 500, 1 000, and 2 000 mA cm−2, respectively, and remarkable stability for 300 h, significantly outperforming those of previously reported OHzS systems and other chemicals-assisted hydrogen production systems. Theoretical calculations reveal that extraordinary performance of HEANFA for OHzS is attributed to its abundant high-activity sites and optimizable reaction pathways in HER and HzOR. In particular, HEANFA enables intelligent migration of key intermediates during HzOR, thereby optimizing the reaction pathways and creating high-activity sites, ultimately endowing the extraordinary performance for OHzS.

Cryoprotectants in biological buffer systems often struggle due to the presence of abundant salts. A precise topological control of polyglycerols provides unique retention-and-release of sodium ions, which activates the formation of hydrogen bonding with ice interfaces. This interaction allows the polymer to inhibit ice growths both in intra- and extracellular spaces, resulting in successful post-thaw cell survival and network-forming functionality.

In this study, a novel phenomenon is identified where precise control of topology and generation of polyglycerol induce the retention of Na+ ions in biological buffer systems, effectively inhibiting ice crystal growth during cryopreservation. Unlike linear and hyperbranched counterparts, densely-packed hydroxyl and ether groups in 4th-generation dendritic polyglycerol interact with the ions, activating the formation of hydrogen bonding at the ice interface. By inhibiting both intra- and extracellular ice growth and recrystallization, this biocompatible dendritic polyglycerol proves highly effective as a cryoprotectant; hence, achieving the cell recovery rates of ≈134–147%, relative to those of 10% dimethyl sulfoxide, which is a conventional cryoprotectant for human tongue squamous carcinoma (HSC-3) cell line and human umbilical vein endothelial (HUVEC) cells. Further, it successfully recovers the network-forming capabilities of HUVEC cells to ≈89% in tube formation after thawing. The Na+ ion retention-driven ice-growth inhibition activity in biological media highlights the unique properties of dendritic polyglycerol and introduces a new topological concept for cell-cryoprotectant development.

A bicontinuous mesoporous carbon nanofiber and carbon nanosheet network is developed to enable high site utilization of single-atom Ni and interfacial CO2 enrichment. The in situ dynamic transformation of the planar Ni−N4 to an out-of-plane configuration is revealed, showing enhanced intrinsic electrokinetics for CO2 reduction. The integrated merits of network support and in situ tailored low-valance-state Ni site endow outstanding performance in acidic CO2-to-CO electrolysis.

Carbon-supported single-atom catalysts exhibit exceptional properties in acidic CO2 reduction. However, traditional carbon supports fall short in building high-site-utilization and CO2-rich interfacial environments, and the structural evolution of single-atom metals and catalytic mechanisms under realistic conditions remain ambiguous. Herein, an interconnected mesoporous carbon nanofiber and carbon nanosheet network (IPCF@CS) is reported, derived from microphase-separated block copolymer, to improve catalytic efficiency of isolated Ni. In IPCF@CS nanostructure, highly mesoporous IPCF hinders stacking of CS that provides additional fully exposed sites and abundant bicontinuous mesochannels of IPCF facilitate smooth CO2 transport. Such unique features enable enhanced Ni utilization and local CO2 enrichment, which cannot be achieved over conventional pore-deficient and discontinuous porous carbon fibers-based supports. In situ X-ray and Infrared spectroscopy coupling constant-potential calculations reveal the dynamic distortion of the planar Ni−N4 to an out-of-plane configuration with expanded Ni−N bond during operating CO2 electroreduction. The potential-driven low-valance-state Ni−N4 possesses enhanced intrinsic electrokinetics for CO2 activation and CO desorption yet inhibiting hydrogen evolution. The favorable electronic and interfacial reaction environments, resulted from the in situ tailored Ni site and IPCF@CS support, achieve an FE of near 100% at 540 mA cm−2, a TOF of 55.5 s−1, and a SPCE of 89.2% in acidic CO2-to-CO electrolysis.

This work proposes a universal synthesis method for rare-earth single-atom catalysts with Cl axially coordination for oxygen reduction reaction (ORR), which exhibits excellent ORR activity and successful applications in zinc-air batteries. The strong d-p orbital coupling between La and Cl significantly improves the electronic structure of the La site, ensuring efficient activation of O2 and suitable adsorption of *OH.

Currently, there are still obstacles to rationally designing the ligand fields to activate rare-earth (RE) elements with satisfactory intrinsic electrocatalytic reactivity. Herein, axial coordination strategies and nanostructure design are applied for the construction of La single atoms (La-Cl SAs/NHPC) with satisfactory oxygen reduction reaction (ORR) activity. The nontrivial LaN4Cl2 motifs configuration and the hierarchical porous carbon substrate that facilitates maximized metal atom utilization ensure high half-wave potential (0.91 V) and significant robustness in alkaline media. The aqueous and flexible Zinc-air battery (ZAB) integrating La-Cl SAs/NHPC as the cathode catalyst exhibits a maximum power density of 260.7 and 68.5 mW cm−2, representing one of the most impressive RE-based ORR electrocatalysts to date. Theoretical calculations have demonstrated that the Cl coordination evidently modulate the electronic structures of La sites, which promoted electron transfer efficiency by d-p orbital couplings. With enhanced electroactivity of La sites, the adsorptions of key intermediates are optimized to alleviate the energy barriers of the potential-determining step. Importantly, this preparation strategy is also successfully applied to other REs. This work provides perspectives for near-range electronic structure modulation of RE-SAs based on a nonplanar coordination micro-environment for efficient electrocatalysis.

Zn1.2Ga1.6Ge0.2O4:Ni2+ nanophosphor with NIR II emission that is responsive to environmental stimuli including temperature and specific solvent variations has been successfully prepared. Leveraging the unique properties of ZGGO:Ni NIR II nanophosphors, an innovative environment-interactive information encryption strategy with multiple dimensions, including wavelength, luminescence lifetime, and external stimuli like temperature and humidity has been developed to enhance information security.

Inspired by the natural responsive phenomena, herein the multiple responsive persistent luminescent Zn1.2Ga1.6Ge0.2O4:Ni2+ (ZGGO:Ni) nanoparticles with near-infrared  (NIR) II emission peak ≈1330 nm derived from the Ni2+ doping through controlled synthesis based on hydrothermal method are obtained. The obtained NIR II persistent luminescent ZGGO:Ni can not only respond to temperature but also the specific solvent stimulus. The results demonstrate that the NIR II persistent luminescence intensity decreases in hydroxyl containing solvent such as water (H2O) and ethyl alcohol (C2H6O), while the PL intensity remains in solvent without hydroxyl groups such as n-hexane (C6H14) and deuterated water (D2O). This NIR II luminescence quenching is attributed to the adsorption of interaction hydroxyl groups in specific solvents with the amino group on the surface of ZGGO:Ni and the subsequent fluorescence resonance energy transfer mechanism. Benefiting from the multiple responsive properties, the obtained NIR II persistent luminescent ZGGO:Ni is utilized for high-order dynamic optical information encryption, providing increased security level. The multi-responsive NIR II persistent luminescence strategy outlined in this study is anticipated to offer a straightforward methodology for optimizing the optical characteristics of NIR II persistent luminescent materials. Moreover, it is set to expand the scope of their applications in the realm of dynamic and environment-interactive information encryption, thereby opening frontiers for their utilization in advanced security measures.

The as-prepared Cu-ZnS exhibits excellent performance in the selective photoreduction of CO₂ to CH₃CH₂COOH, achieving a production rate of 0.45 µmol h−¹, which increases to 16.9 µmol h−¹ with triethanolamine while maintaining a high product selectivity of 97%. Using in situ experimental techniques and theoretical calculations, the key C₃ intermediates are identified providing crucial insights into the CH₃CH₂COOH formation pathway.

The direct photocatalytic conversion of CO2 and H2O into high-value C3 chemicals holds great promise but remains challenging due to the intrinsic difficulty of C1–C1 and C2–C1 coupling processes and the lack of clarity regarding the underlying reaction mechanisms. Here, the design and synthesis of a Cu-ZnS photocatalyst featuring dispersed Cu single atoms are reported. These Cu single atoms are coordinated with S atoms, forming unique Cu-S-Zn active units with tunable charge distributions that interact favorably with surface-adsorbed intermediates. This configuration stabilizes the *COHCO intermediate and facilitates its subsequent coupling with *CO to form *COCOHCO both thermodynamically and kinetically favorable on the Cu-ZnS surface. Notably, multiple critical C3 intermediates, including *COCOHCO, *OCCCO, and *CHCHCO, are identified, providing a clear reaction pathway for CO2 to CH3CH2COOH conversion. The Cu-ZnS photocatalyst achieves a CO2 to CH3CH2COOH conversion rate of 0.45 µmol h−¹ with an electron selectivity of 91.2%. Remarkably, in the presence of triethanolamine, the production rate increases to 16.9 µmol h−¹ with a selectivity of 99.8%. These findings underscore the importance of modulating multicarbon coupling processes to enable the efficient photocatalytic transformation of CO2 into C3 products, paving the way for future advancements in sustainable chemical synthesis.

A universal phase-engineering strategy is reported to achieve mechanically robust hydrogels by tuning microphase separation using cellulose nanocrystal (CNC) and common compatible polymer systems. CNC plays a crucial role in contributing to mitigating microphase separation for strengthening and toughening hydrogels. Benefiting from the CNC-mitigated microphase separation structure, the enabling hydrogel exhibits unprecedented combinations in mechanical properties.

As a common natural phenomenon, phase separation is exploited for the development of high-performance hydrogels. Using supersaturated salt to create microphase-separated hydrogels with strengthened mechanical properties has gained widespread attention. However, such strengthened hydrogel loses its intrinsic flexibility, making the phase separation strategy unsuitable for the fabrication of stretchable and tough hydrogels. Here, a phase-engineering design strategy is introduced to produce stretchable yet tough hydrogels using supersaturated NaAc salt, by leveraging the hydration effect of cellulose nanocrystal (CNC) to mitigate microphase separation. The CNC-mitigated microphase-separated hydrogel presents unprecedented mechanical properties, for example, tensile strength of 1.8 MPa with a fracture strain of 4730%, toughness of 43.1 MJ m−3, fracture energy of 75.4 kJ m−2, and fatigue threshold up to 3884.7 J m−2. Furthermore, this approach is universal in synthesizing various microphase separation-enhanced polymer gels, including polyacrylic acid, poly(acrylic acid-co-acrylamide), gelatin, and alginate. These advancements provide insights into the incorporation of CNC-mediated microphase separation structures in hydrogels, which will foster the future development of high-performance soft materials.

This paper investigates the influence of thickness on the properties of thin epitaxial Bi films. It discusses results from optical, vibrational, and structural analyses, highlighting notable changes in dielectric function, phonon frequencies, and Peierls distortion. The competition between electron localization and delocalization is emphasized, showing how thickness reduction can tailor material properties without changing stoichiometry.

A systematic study of the impact of film thickness on the properties of thin Bi films is presented. To this end, epitaxial films of high quality have been grown on a Si (111) substrate with thicknesses ranging from 1.9 to 29.9 nm. Broadband optical spectroscopy reveals a notable decline in the optical dielectric constant and the absorption peak height as the film thickness decreases, alongside a shift of the absorption maximum to higher photon energies. Raman and pump-probe spectroscopy show that the phonon mode frequencies increase upon decreasing film thickness, with the in-plane mode frequency rising by 10% from the thickest to the thinnest sample. The X-ray diffraction analysis reveals an increasing Peierls distortion for thinner films, explaining the observed property changes. Quantum chemical bonding analysis and density functional theory calculations show that the properties of thin bismuth are influenced by the interplay between electron localization and delocalization, characteristic of metavalently bonded solids. This study shows that for solids that utilize metavalent bonding, a thickness reduction leads to significant property changes. The effect can even be employed to tailor material properties without the need to change material stoichiometry.

Machine learning has been successfully employed to optimize the compositions of multicomponent electrolytes. As a result, the as-obtained novel Zn-air batteries can deliver superior battery reversibility and stability (1700 h at 2 mA cm−2 and 1400 h at 20 mA cm−2), and greatly improved round-trip efficiency as high as 76.3%.

Aqueous alkaline Zn-air batteries (ZABs) have garnered widespread attention due to their high energy density and safety, however, the poor electrochemical reversibility of Zn and low battery round-trip efficiency strongly limit their further development. The manipulation of an intricate microscopic balance among anode/electrolyte/cathode, to enhance the performance of ZABs, critically relies on the formula of electrolytes. Herein, the Bayesian optimization approach is employed to achieve the effective design of optimal compositions of multicomponent electrolytes, resulting in the remarkable enhancement of ZAB performance. Notably, ethylene glycol has been successfully employed as both electrolyte additive and fuel, playing key roles in changing the reaction pathways of ZABs, especially the storage form of discharge products from ZnO deposition on the anode to Zn2+-based hybrid particle colloids in the electrolyte. As a result, the as-obtained novel ZABs can deliver superior battery reversibility and stability (1700 h at 2 mA cm−2 and 1400 h at 20 mA cm−2), greatly improved round-trip efficiency as high as 76.3%, and even continuous discharge until complete Zn anode depletion. This work has demonstrated enormous potential for long-term energy storage applications and holds promise for bringing new opportunities to the development of ZABs.

An ultra-stiff yet super-elastic aerogel is realized through the design of a topological cellular hierarchy, enabling it to support high loads through preferably reversible buckling deformation, thereby overcoming the intrinsic conflict between high stiffness and superior recoverability.

Lightweight cellular materials with high stiffness and excellent recoverability are critically important in structural engineering applications, but the intrinsic conflict between these two properties presents a significant challenge. Here, a topological cellular hierarchy is presented, designed to fabricate ultra-stiff (>10 MPa modulus) yet super-elastic (>90% recoverable strain) graphene aerogels. This topological cellular hierarchy, composed of massive corrugated pores and nanowalls, is designed to carry high loads through predominantly reversible buckling within the honeycomb framework. The compressive modulus of the as-prepared graphene aerogel is nearly twice that of conventional graphene aerogel. This high-stiff graphene aerogel also exhibits exceptional mechanical recoverability, achieving up to 60% strain recovery over 10 000 fatigue cycles without significant structural failure, outperforming most previously reported porous lattices and monoliths. It is further demonstrated that this graphene aerogel exhibits superior energy dissipation and anti-fatigue dynamic impact properties, with an energy absorption capacity nearly an order of magnitude greater than that of conventional aerogels. These exceptional properties of the topological cellular graphene aerogel open new avenues for high-energy bullet protection, offering great promise for the development of lightweight, armor-like protective materials in transportation and aerospace applications.

Concurrent superconductivity and negative photoconductivity (NPC) are discovered in PbSe0.5Te0.5 accompanying pressure-induced phase transitions. Both have a strong structure dependence and are jointly mediated by electron-phonon interplay, which is switchable via illumination or cooling at high-pressure. New findings offer more new insights into understanding the essence of photoelectric-lattice coupling and developing versatile materials of lead chalcogenides.

Concurrent superconductivity and negative photoconductivity (NPC) are rarely observed. Here, the discovery in PbSe0.5Te0.5 of superconductivity and photoconductivity transitions between positive photoconductivity (PPC) and NPC during compression is reported to ≈40 GPa and subsequent decompression, which are also accompanied by reversible structure transitions (3D Fm3¯${{\bar{3}}}$m ⇌ 2D Pnma ⇌ 3D Pm3¯${{\bar{3}}}$m). Superconductivity with a maximum T c of ≈6.7 K coincides with NPC and structure transition of Pnma to Pm3¯${{\bar{3}}}$m at ≈18 GPa and the latter phase is preserved down to ≈5 GPa with enhanced T c of ≈6.9 K during decompression. The observations imply the simultaneous superconducting and photoconductive transitions are closely related to the metallic Pm3¯${{\bar{3}}}$m phase. First-principles calculations suggest the enhanced p-p hybridization and charge transfer between Pb-5p and ligand-p orbitals near the Fermi surface play key roles in electron-phonon interaction of mediating the Cooper pairs in PbSe0.5Te0.5. Hall coefficient measurements reveal that photothermal effect enhances electron-phonon interplay, which decreases carrier concentration and mobility and results in the reversal of PPC-NPC. Structure-dependent superconductivity and NPC are jointly mediated by electron-phonon interplay, which is tunable through illumination or cooling at high-pressure. The findings shed light on the origin of superconductive and photoconductive transitions in versatile materials of lead chalcogenides.

A “smart” n-type conjugated polymer with glycolated side chains that forms a more ordered assembly when electrochemically doped, is reported along with a newly synthesized p-type conjugated polymer. The n-type and p-type polymers complement each other perfectly to construct an organic complementary inverter, achieving a record voltage gain of 307 VV−1.

The charge transport of channel materials in n-type organic electrochemical transistors (OECTs) is greatly limited by the adverse effects of electrochemical doping, posing a long-standing puzzle for the community. Herein, an n-type conjugated polymer with glycolated side chains (n-PT3) is introduced. This polymer can adapt to electrochemical doping and create more organized nanostructures, mitigating the adverse effects of electrochemical doping. This unique characteristic gives n-PT3 excellent charge transport in the doped state and reversible ion storage, making it highly suitable as an n-type organic mixed ionic-electronic conducting (OMIEC) material. n-PT3 exhibits a high electron mobility of µ ≈ 1.0 cm2 V−1 s−1 and a figure of merit value of µC* ≈ 100 F cm−1 V−1 s−1, representing one of the best results for n-type OMIEC materials. A new p-type OMIEC polymer has been synthesized as the channel material for constructing a complementary inverter to match the n-type OECT channel layer based on n-PT3. As a result, a voltage gain value of up to 307 VV−1 has been achieved, which is a record value for sub−1 V complementary inverters based on OECTs. This work offers valuable insights into designing electrochemical doping adaptive n-type OMIEC materials and fabricating high-gain organic complementary inverters.