The development of low-cost, high-activity, and durable integrated bifunctional flexible air electrodes for use in Zn-air batteries is both challenging and important. We report a simple and scalable electropolymerization method used to prepare an electrode material comprising heavily N-doped carbon covering single-walled carbon nanotube (N/C-SWCNT) networks. The resulting core/shell structure of the hybrid electrode enabled the flexibility, mechanics, and three-dimensional interconnected porous structure of SWCNT films while containing abundant pyridinic N, which provided excellent catalytic activity for both the oxygen reduction and evolution reactions (overpotential gap = 0.76 V). A binder-free Zn-air battery using the N/C-SWCNT film as an oxygen electrode was assembled and showed a high peak power density of 181 mW/cm2, a high specific capacity of 810 mAh/g and stable discharge‒charge cycling performance. We also constructed a flexible solid-state Zn-air battery featuring not only a high power density of 22 mW/cm2 but also good flexibility and stability.

Bioinspired from structural coloration of butterfly wing structure, this work aims to fabricate nanoporous chitosan for UVC reflection. By taking advantage of self-assembled polystyrene-b-polydimethylsiloxane (PS-b-PDMS) with double gyroid texture followed by hydrofluoric acid etching of PDMS block, nanoporous PS with well-defined nanochannels can be fabricated, and used as a template for templated crosslinking reaction of chitosan through a multiple pore-filling process. Well-ordered nanoporous chitosan with shifting networks in nanoscale can be successfully fabricated after removal of the PS template. With the low absorption of chitosan in the ultraviolet region and the shifting networks for opening the bandgap, it is appealing to exploit the nanonetwork chitosan as high reflective materials for UVC optical devices, as evidenced by finite-difference time-domain (FDTD) simulation and optical measurements experimentally.

Herein, this work aims to develop a facile method for the fabrication of metallic mechanical metamaterial with a well-ordered diamond structure from a bottom-up approach using a self-assembled block copolymer for templated electrochemical deposition. By controlling the effective volume fraction of PDMS in PS-b-PDMS via solvent annealing followed by HF etching of PDMS, it is feasible to obtain nanoporous PS with diamond-structured nanochannels and used it as a template for templated electrochemical deposition. Subsequently, well-ordered nanonetwork gold (Au) can be fabricated. As evidenced by nanoindentation and micro-compression tests, the mechanical properties of the diamond-structured Au after removal of PS give the combination of lightweight and mechanically robust characteristics with an exceptionally high reduced elastic modulus of 11.9 ± 0.6 GPa and yield strength of 193 ± 11 MPa above the Hashin-Shtrikman upper bound of 72 MPa with a bending-dominated structure at equivalent density. The corresponding deformation mechanism can be elucidated by morphological observations experimentally and finite element analysis (FEA) numerically. This work demonstrates the bottom-up approach to fabricating metallic monolith with diamond structure in the nanoscale, giving a superior performance as mechanical metamaterials.

During wound healing, oxygen availability and the anti-inflammatory microenvironment play an important role in the formation of new tissue. However, providing continuous and controllable oxygen around the injured tissue while inhibiting inflammation and realizing the synergistic effect of oxygen supply and anti-inflammation is still a major problem affecting the regeneration and repair of wound tissue. Inspired by skin wound pathology and the inflammatory microenvironment, a photothermal response-assisted strategy was developed in this study. We prepared a composite hydrogel system of polydopamine-hyaluronic acid (PDA-HA) hydrogel-loaded calcium peroxide-indocyanine green combined with lauric acid and manganese dioxide (CaO2-ICG@LA@MnO2) nanoparticles that showed excellent photothermal performance under near-infrared (NIR) irradiation and realized the on-off release of oxygen and reactive oxygen species (ROS). Controllable and sustainable oxygen release can promote the regeneration and repair of damaged tissue, and the generated ROS can effectively inhibit the outbreak of inflammation at the initial stage of wound healing. We believe that the system we have developed can be used in a new approach for treating chronic wounds.

A noble surface engineering method was developed to create a binder-free flexible electrode comprising Ti3C2Tx MXene/carbon nanofibers (MCNFs) covered by amorphous RuOx with a combined electrospinning and hydrothermal process. Utilizing the hydrophilicity of the MXene on/in the MCNFs, RuOx was easily coated on the surfaces of the MCNFs through oxygen-mediated chemical bonding between the functional groups of the MXene and Ru ions. A structural analysis revealed that the MXene acted as a growth template for RuOx and that the formed RuOx had an amorphous and disordered state in the composite electrode, which impacted the electrochemical performance. The electrochemical tests showed that these composite electrodes improved the electrochemical performance, with a two-fold increase in the gravimetric capacitance (279.4 F/g at 2 mV/s) relative to that of pristine MCNFs, a wide potential window (from 0.7 to 1 V) providing a superior energy density of 8.5 Wh/kg at a power density of 85.8 W/kg, as well as long-term cycling stability (99% after 10,000 cycles). The synergetic effect of the RuOx and MXene in the composite electrodes was attributed to an enhanced pseudocapacitive reaction. Our novel electrodes and fabrication method confirm the great potential of CNF-based composites for the development of high-performance binder-free electrodes for supercapacitors.

Deoxygenation of bioderived lipids into renewable transportation fuels is a promising route to decreasing the dependence on fossil sources. Ni-based catalysts are high performing and cost-effective in deoxygenation reactions but suffer from severe sintering and aggregation. Herein, a ligand-chelating impregnation method was used to prepare highly dispersed Ni nanoclusters on a two-dimensional (2D) ITQ-2 zeolite. Comprehensive characterization was utilized to monitor the changes in the organometallic precursors during activation and to investigate their impact on the dispersion of the Ni nanoclusters on the ITQ-2 zeolite. The high external surface area and abundant surface defects of the 2D support enhanced the dispersion and immobilization of the Ni nanoclusters and outperformed conventional zeolites. The protection of the Ni2+ cations by the organic ligand suppressed the aggregation of Ni species during the activation processes, thereby leading to the formation of uniformly distributed Ni nanoclusters on the ITQ-2 zeolite. Due to the highly dispersed Ni nanoclusters and immobilization on the 2D zeolite, the Ni/ITQ-2-co material prepared by the ligand-chelating impregnation approach showed outstanding activity and stability for conversions of stearic acid or palm oil to diesel range alkanes. This work provides a rational design and precise modulation of metal-based catalysts for the production of renewable diesel.

Smart photonic hydrogels based on two-dimensional photonic crystals (2DPC) provide a promising sensing platform for constructing novel chemical and biological sensors due to their facile optical signal readout and highly sensitive responsivity toward target analytes. Aptamers, as recognition elements with high selectivity and affinity, are extensively used to construct a variety of sensors. Herein, we developed two partially base complementary aptamer-functionalized 2DPC hydrogels as aptasensors for the detection of thrombin (TB) in human serum. The photonic hydrogel aptasensors swelled upon exposure to TB solution, leading to an increase in the particle spacing of the 2DPCs. The particle spacing changes were acquired by simply measuring the diameters of the Debye ring diffracted by the 2DPCs without the requirement of sophisticated instruments. The aptasensor swelling resulted from the decrease in the hydrogel cross-linking density induced by the specific binding between one of the aptamers and TB and the increase in hydrogel mixing free energy induced by the introduction of TB. The particle spacing increase of the optimized aptasensor was linear over the TB concentration range of 1–500 nM, and the limit of detection was 0.64 nM. The constructed 2DPC hydrogel aptasensor was used to detect TB in human serum and achieved recoveries of 95.74–104.21% and a relative standard deviation of 2.52–6.58%, showing the practicability and accuracy of the sensor. The aptamer-actuated 2DPC hydrogel biosensor provides a new strategy for designing other target molecule-sensitive aptasensors, showing great potential for development into home kits.

Layered potassium manganese oxides are promising candidates for use in aqueous supercapacitors owing to their wide potential windows, layered feature, and Faradaic redox reactions that occur on surfaces and in bulk regions. However, the practical application is hindered by rapid performance degradation due to their inherently low electrical conductivities and inferior structural stabilities. Here, we develop ultralong nanobelts comprising hydrated Na-intercalated oxygen-deficient potassium manganese oxide (H-Na-D-KMO), in which the Na+ ions are preintercalated and synchronously induce the generation of oxygen vacancies, as high-energy-density and durable electrodes for Mg-ion supercapacitors. The experimental results indicated that preintercalation of Na+ ions and formation of oxygen vacancies improved the electrical properties and ion diffusion, which accounted for the fast reaction kinetics and good cycling performance of H-Na-D-KMO. The optimized H-Na-D-KMO delivered a significantly enhanced specific capacitance and cycling performance compared to those of pure H-KMO. Asymmetric supercapacitors with H-Na-D-KMO as the cathode and as-prepared MoO2@carbon as the anode exhibited an ultrahigh energy density of 108.4 Wh kg–1 at 11,000 Wh kg−1, which is superior to most supercapacitors reported in the literature. Moreover, the assembled device exhibited good cycling stability for over 5000 cycles with a fading rate of 0.002% per cycle and good mechanical flexibility, which opens an avenue for further advancements in high-energy supercapacitors.

Cisplatin-based nanoparticles show good potential in enhancing the effect of nasopharynx carcinoma (NPC) therapy but are still limited by their low radiation sensitization and poor tumor targeting ability. Herein, an ingenious design of multifunctional superparamagnetic iron oxide nanoparticle (SPION)@polymer hybrid nanosensitizer (SPHN) with enhanced radiosensitization and dual-targeting capability is described. SPHN have a core-shell structure, in which radiosensitizer superparamagnetic iron oxide particle (SPION) and cis-platinum (CDDP) are encapsulated in RGD-conjugated amphiphilic block copolymers. These unique structures endow SPHN with outstanding radiosensitization and tumor targeting abilities. When combined with X-rays, SPHN showed strong promotion of the apoptosis of CNE-1 cells in vitro. In addition, RNA-seq and KEGG enrichment analyses indicated that the PI3K-Akt and TNF signaling pathways were closely related to the molecular mechanism of SPHN in chemoradiotherapy. Furthermore, gene set enrichment analysis (GSEA) revealed that SPHN + X-rays treatment decreased translation initiation pathways and the cytoplasmic translation pathway. Through a combination of radiation and chemotherapy, SPHN can achieve remarkable inhibition of tumor growth in vivo, making this nanotechnology a general platform for the chemoradiation therapy of NPC in the future.

Inorganic–organic hybrid materials have promising properties for bone repair because of the covalent bonding between their inorganic and organic phases. This desirable interaction allows the limitations of composite materials, such as inhomogeneous biodegradation rates and nonbiointeractive surfaces, to be overcome. In this study, a polycaprolactone (PCL)-based polyurethane (PU) with an organosilane functional group was synthesized for the first time. Thereafter, a biodegradable PU-silica hybrid was produced through the sol-gel process. The PU-silica hybrid was not only flexible and fully biodegradable but also possessed shape memory ability. In addition, allophanate bonding enabled the silane coupling agent to induce increased crosslinking between the polymer and silica network, as well as between polymer and polymer. Accordingly, the sol-to-gel gelation time required to produce the hybrids was very short, which allowed the production of 3D porous hybrid scaffolds through a simple salt-leaching process. A hybrid scaffold with a 30 wt. % silica composition was the most ideal bone regenerative scaffold since it was able to withstand thermal deformation with promising mechanical properties. Moreover, the hybrid scaffold induced osteogenic differentiation and angiogenesis to accelerate bone regeneration.

DNA origami technology enables the precise assembly of well-defined two-dimensional and three-dimensional nanostructures with DNA, an inherently biocompatible material. Given their modularity and addressability, DNA origami objects can be used as scaffolds to fabricate larger higher-order structures with other functional biomolecules and engineer these molecules with nanometer precision. Over the past decade, these higher-order functional structures have shown potential as powerful tools to study the function of various bio-objects, revealing the corresponding biological processes, from the single-molecule level to the cell level. To inspire more creative and fantastic research, herein, we highlight seminal works in four emerging areas of bioapplications of higher-order DNA origami structures: (1) assisting in single-molecule studies, including protein structural analysis, biomolecule interaction analysis, and protein functional analysis, (2) manipulating lipid membranes, (3) directing cell behaviors, and (4) delivering drugs as smart nanocarriers. Finally, current challenges and opportunities in the fabrication and application of DNA origami-based functional structures are discussed.

High-performance functional fibers play a critical role in various indispensable fields, including sensing, monitoring, and display. It is desirable yet challenging to develop conductive fibers with excellent mechanical properties for practical applications. Herein, inspired by the exquisite fascicle structure of skeletal muscle, we constructed a high-performance bacterial cellulose (BC)/carbon nanotube (CNT) conductive fiber through in situ biosynthesis and enhancement of structure and interaction. The biosynthesis strategy achieves the in situ entanglement of CNTs in the three-dimensional network of BC through the deposition of CNTs during the growth of BC. The structure enhancement through physical wet drawing and the interaction enhancement through chemical treatment facilitate orientation and bridging of components, respectively. Owing to the ingenious design, the obtained composite fibers integrate high strength (939 MPa), high stiffness (52.3 GPa), high fatigue resistance, and stable electrical performance, making them competitive for constructing fiber-based smart devices for practical applications.

Metal halide perovskites can be readily synthesized, they exhibit tunable physical properties and excellent performance, and they are heavily studied optoelectronic materials. Compared to the typical three-dimensional perovskites, morphological-level one-dimensional (1D) nanostructures enable charge transport and photon propagation with low exciton binding energies and long charge-carrier diffusion lengths, while molecular-level 1D nanostructures exhibit good compositional and structural flexibilities, highly tunable bandgaps, strong quantum confinement effects, and excellent ambient stabilities. The 1D natures of these emerging halide perovskites enhance the performance of optoelectronic devices. Herein, we highlight recent progress realized in the syntheses and characterizations of both morphological- and molecular-level 1D halide perovskites with tunable structures, compositions, and properties, as well as their photovoltaic, light-emission, and photodetection applications. In addition, current challenges, future prospects, and promising research directions are discussed to provide guidance in advancing the field of 1D perovskites.

The barocaloric effect (BCE) has emerged as an intense research topic in regard to efficient and clean solid-state refrigeration. Materials with solid-liquid phase transitions (SL-PTs) usually show huge melting entropies but cannot work in full solid-state refrigeration. Here, we report a colossal barocaloric effect realized by exploiting high entropy inherited from huge disorder of liquid phase in amorphous polyethylene glycol (PEG), which is solidified by introducing 5 wt.% polyethylene terephthalate (PET). Transmission electron microscopy (TEM) combined with X-ray diffraction (XRD) demonstrates the amorphous nature of the high-temperature phase after fixation by PET. Although PEG loses its –OH end mobility in amorphous solid, high entropy still retains owing to the retained high degrees of freedom of its molecular chains. The remaining entropy of amorphous PEG is up to 83% of that of liquid PEG in PEG10000/PET15000, and the barocaloric entropy change reaches ΔSp ∼ 416 J·kg−1·K−1 under a low pressure of 0.1 GPa, which exceeds the performance of most other BCE materials. Infrared spectra combined with density function theory (DFT) calculations disclose conformational change from the liquid to amorphous state, which explains the origin of the large entropy retained and hence the colossal BCE of the solidified PEG. This research opens a new avenue for exploring full solid-state barocaloric materials by utilizing genetic high entropy from huge disordering of liquid phases in various materials with SL-PTs.

In this work, we develop a new type of mesoporous 2D N, B, and P codoped carbon network (NBP-CNW) arranged into high-order 3D nanotube arrays (NTAs), which are wrapped onto a flexible carbon fiber microelectrode, and this microelectrode is employed as a high-performance carbon-based nanocatalyst for electrochemical biosensing. The NBP-CNW-NTAs synthesized by a facile, controllable, ecofriendly and sustainable template strategy using ionic liquids as precursors possess a high structural stability, large surface area, abundant active sites, and effective charge transport pathways, which dramatically improve their electrocatalytic activity and durability in the redox reaction of cancer biomarker H2O2. Benefiting from these unique structural merits, superb electrochemical activity and good biocompatibility, the NBP-CNW-NTAs-modified microelectrode demonstrates excellent sensing performance toward H2O2 and is embedded in a homemade microfluidic electrochemical biosensor chip for the real-time tracking of H2O2 secreted from different live cancer cells with or without radiotherapy treatment, which provides a new strategy for distinguishing the types of cancer cells and evaluating the radiotherapeutic efficacy of cancer cells. Furthermore, the functional microelectrode is integrated into an implantable probe for the in situ detection of surgically resected human specimens to distinguish cancer tissues from normal tissues. These will be of vital significance for cancer diagnoses and therapy in clinical practice.

Discovering and understanding anomalous anisotropic magnetoresistance (AMR) effects are important aspects of studying the nature of modulated transport. The anisotropic transport coefficients of topological systems are often useful for mapping hidden phases and characterizing topological phase transitions and the evolution of topological electrons. Here, we report an unusual change in the AMR effect in HoPtBi. Remarkably, the AMR exhibits transitions from a quasi-twofold to fourfold symmetry and finally forms a stable rotated fourfold symmetry with increasing magnetic fields. The evolution analysis from the three-dimensional (3D) mapping experiments confirms that it is an intrinsic 3D effect. Fourier transformation analysis indicates that the superposition of C2, C4, and C6 signals with phase angle transitions leads to the novel AMR. All transitions are summarized as symmetry rotation or the inversion of peaks and valleys. By combining the features of band structures and AMR, we evaluate the possible origin of this symmetry rotation and attribute it to the topological band change. This work provides insight into the anomalous AMR effect of topological materials and is useful for understanding the evolution of topological bands in a magnetic field. We propose that other rare-earth half-Heusler alloys can potentially exhibit similar phenomena.

A novel chemical vapor method is developed to synthesize ultrastable lead halide perovskite-zeolite (ZSM-5) composites, in which CsPbX3 (X = Cl, Br, I) perovskite quantum dots (QDs) are grown in situ in the nanopores of the ZSM-5 substrate. The key chemical reaction between PbBr2 vapor and the Si–O network in ZSM-5 leads to collapse of the initial zeolite crystal structure, realizing effective confinement and encapsulation of CsPbBr3 QDs and boosting their stability under harsh conditions, including heat, water, polar solvents, and ultraviolet (UV) light. At the same time, the acquired encapsulation structure possesses the channels needed for halogen exchange to regulate the halide ratios of the CsPbX3-ZSM-5 composites. The synthesized CsPbX3-ZSM-5 composites exhibit tunable emission from 400 to 700 nm and narrow full-widths at half-maximum (FWHM). To demonstrate the commercial potential, CsPbX3-ZSM-5 composites synthesized on a large scale are applied in white light-emitting diodes (WLEDs) and multicolor-coded anti-counterfeiting inks.

Flexible Zn–air batteries (FZABs) exhibit low cost and inherent safety and have potential for application in wearable electronic devices. Nevertheless, balancing the high energy density and flexibility of the self-supported electrodes in FZABs is still a challenge. Herein, we develop a novel superassembly strategy for the preparation of N, S-codoped porous carbon frameworks (NS@CFs) as cathodes in FZABs. Benefiting from the abundant heteroatom defect sites, NS@CF exhibits excellent electrocatalytic performance for the oxygen reduction reaction (ORR), including high electrochemical activity and long-term stability. When used as the cathode in a liquid flowing ZAB, NS@CF exhibited a power density of 221 mW cm−2 and achieved a 60% improvement over Pt/C-based ZABs. This new ZAB exhibited a high specific capacity of 792 mA h gZn−1, excellent long-term durability and cycling stability, which is superior to those of ZABs assembled with commercial Pt/C cathodes. In addition, the flexible NS@CF with directional channels can be used as independent air cathodes for FZABs, where it provides small charge/discharge voltage gaps, a power density of 49 mW cm−2 and outstanding cycling stability. This work provides a novel strategy for designing and fabricating highly efficient integrated electrodes for flexible and wearable electrochemical devices.

Capacitors based on ABO3-type perovskite oxides show considerable promise for overcoming the limitations of nanoscale integration with dynamic random access memory (DRAM) devices. Among the thermodynamically stable perovskite oxides, titanates (ATiO3) exhibit high dielectric permittivity in metal–insulator–metal (MIM) configurations. However, their performance in mitigating the large leakage current caused by their narrow bandgap (3 eV) remain under scrutiny. Herein, substantially enhanced dielectric properties of an epitaxial SrRuO3/Ba0.5Sr0.5TiO3/SrRuO3 MIM capacitor with a thin dielectric layer (10 nm) are reported. The dielectric/electrode heterointerface was engineered to realize a capacitor with a low leakage current and high dielectric permittivity. A pit-free and stoichiometric SrRuO3 bottom electrode with an atomically smooth surface was exploited to suppress defect formation at the heterointerface. The critical roles of oxygen vacancies and substituted transition-metal atoms in determining the leakage current were assessed, and a strategy for reducing the leakage current via interface engineering was established. Consequently, a dielectric permittivity of 861 and a leakage current density of 5.15 × 10−6 A/cm2 at 1 V were obtained with the thinnest dielectric layer ever reported. Our work paves the way for the development of perovskite-oxide-based capacitors in next-generation DRAM memories.

The hierarchical anisotropy of a biotissue plays an essential role in its elaborate functions. To mimic the anisotropy-based functions of biotissues, soft and wet synthetic hydrogels with sophisticated biotissue-like anisotropy have been extensively explored. However, most existing synthetically manufactured anisotropic hydrogels exhibit fundamental anisotropy and poor mechanical toughness characteristics. In this paper, natural/synthetic hybrid double-network (DN) hydrogels with hierarchical anisotropy and high toughness characteristics are reported. These DN gels are prepared directly by using a squid mantle as an anisotropic soft bioproduct for the primary network and polyacrylamide (PAAm) as a synthetic polymer for the secondary network. The obtained squid/PAAm DN gel maintains the complex orientation of the muscle fibers of the squid mantle and exhibits anisotropic, enhanced mechanical properties and excellent fracture resistance due to its unique composite structure. This hybrid strategy provides a general method for preparing hydrogels with elaborated anisotropy and determining functions derived from the anisotropy.