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In olivine phosphate cathode materials, the biaxial tensile strain perpendicular to the direction of Li+ ion migration is the most favorable for Li+ ion migration, and the b-axial strain has a greatest effect on the Li+ ion migration barrier.

Phthalate esters (PAEs) and bisphenol A (BPA) are endocrine-disrupting chemicals (EDCs), which are widely used in the production of food plastic packaging and easily migrate to food.

A series of “pure” hard carbon models, built using C60 as precursor, help to correlate the alkali-ion (e.g., Li+, Na+, and K+) storage behaviour of hard carbons to orbital hybridization states of carbon atoms.

Although room-temperature phosphorescence (RTP) organic materials are a widely-studied topic especially popular in recent decades, long-lived RTP able to fulfil broad time-resolved application requirements reliably, are still rare. Polymeric materials doped with phosphorescent chromophores generally feature high productivity and diverse applications, compared with their crystalline counterparts. This study proves that pure polycyclic aromatic hydrocarbons (PAHs) may even outperform chromophores containing hetero- or heavy-atoms. Full-color (blue, green, orange and red) polymer-PAHs with lifetimes5000 ms under ambient conditions are constructed, which provide impressive values compared to the widely reported polymer-based RTP materials in the respective color regions. The polymer-PAHs could be fabricated on a large-scale using various methods (solution, melt and

The unstable electrode–electrolyte interphase of Li-rich cathodes limit their application. Here an ultrathin Li2SiO3 protective layer with super toughness and functionality is constructed on the surface of Li-rich cathodes by atom layer deposition.

Next-generation photocatalysts are continuously inspired by natural nanostructures to enhance their characteristics, harness the inherent natural structure properties and boost the photocatalytic performance for efficient degradation of persistent organic pollutants (POPs).

Robust and color-tunable afterglows are achieved from guanidine derivative solids even in single crystals through synergistic clustering and hydrogen-bonding effects.

A novel gel electrolyte with a 3D compact-stacked microsphere matrix is synthesized to realize long cycling stability of LMBs.

Combining density functional theory (DFT) and semi-classic Boltzmann transport theory, we report the thermoelectric (TE) performance of a family of two-dimensional (2D) group IB-selenides XSe (X = Cu, Ag, Au). The results show that these monolayers exhibit small and anisotropic phonon velocities (0.98-3.84 km s

Methylenecyclobutane containing tetrasubstituted alkenyl nitriles were synthesized via strain-release driven cyanocarbene addition reaction of [1.1.1]propellane under metal-free and mild conditions.

In recent years, solar steam generation has been one of the most promising and sustainable techniques for water desalination. However, the heat loss to bulk water dramatically decreases the evaporation rate. Besides, salt deposition on the evaporation surface during brine treatment limits the long-term operation of evaporators. Herein, solar evaporators with a horizontal channel-like framework are reported and high efficiency and outstanding salt resistance are achieved. Firstly, eggplants with a hollow fiber alignment structure were carbonized as CEP evaporators. The CEP-H evaporator with a horizontal fiber growth direction shows a high evaporation efficiency of 90.6% and excellent salt resistance when treating high-salinity brine (20 wt%). The low thermal conductivity perpendicular to the fiber growth direction impedes the conductive heat transfer into bulk water, and fast water transport along the fiber growth direction is beneficial for salt resistance. In addition, a proof-of-concept evaporator polypyrrole-coated polypropylene hollow fiber membrane with a horizontal channel-like framework (PPy/PP-H) has also been developed. This hollow fiber membrane shows a high evaporation rate of 1.64 kg m

For reaching high-performance of electrode materials, it is generally believed that understanding the structure evolution and heterogeneous alignment effect is the key. Presently, a very simple and universally applicable self-healing method is investigated to prepare defect-free Prussian blue analogs (PBAs) that reach their theoretical capacity as cathode materials for sodium-ion batteries (SIBs). For direct imaging of the local structure and the dynamic process at the atomic scale, we deliver a fast ion-conductive nickel-based PBA that enables rapid Na+ extraction/insertion within 3 minutes and a capacity retention of nearly 100% over 4000 cycles. This guest-ion disordered and quasi-zero-strain nonequilibrium solid–solution reaction mechanism provides an effective guarantee for realizing long-cycle life and high-rate capability electrode materials that operate via reversible two-phase transition reaction. Unconventional materials and mechanisms that enable reversible insertion/extraction of ions in low-cost metal–organic frameworks (MOFs) within minutes have implications for fast-charging devices, grid-scale energy storage applications, material discovery, and tailored modification.

Structural and pigment colorations are omnipresent in insects, producing a range of colors for camouflage, warning, mimicry and other strategies necessary for survival. Structural coloration has attracted a lot of attention due to its significance in biophotonics, biomimetics and even esthetic appeal. The coupling of structural and pigment colorations has been largely unnoticed. Herein we show how pigments, scattering and interference work together in two-dimensional waveguiding structures to produce the coloration of Jordanita globulariae (Huebner, 1793), a moth whose forewings sparkle with slightly iridescent green scales. We show that subwavelength structures scatter and couple light into a concave multilayered structure to enhance the absorption of pigments. A finite element method (FEM) model, adequately describing the photonic properties of J. globulariae, was developed based on the nanoscale architecture of the insect's wing scales. The principle of absorption enhanced by scattering and waveguiding is present in many insect species and might be imitated to tailor the spectral properties of optical devices.

Surface enhanced Raman scattering (SERS) has attracted much research attention for analysis and trace detection. In this work, we fabricated a gyroid-structured Au–Ag bimetal plasmonic material GSPMMs@Au by incorporating gyroid-structured silver periodic metallic materials (GSPMMs) with Au nanoparticles (NPs). By controlling the galvanic reaction time, we found that the highest surface plasmonic resonance enhancement among all the samples can be acquired with a deposition time of 50 s (GSPMMs@Au50). Finite-difference time domain simulation results prove that plasmonic coupling between the Au–Ag interface dramatically enhances the SERS performance. The SERS detection limit of bis(2-ethylhexyl) (DEHP) molecules based on GSPMMs@Au50 was 3.4 × 10−18 M, which is the best result among recently published studies.

Harvesting energy from sunlight is an essential component of thermal load in an outdoor environment. Controlling the solar heating effects is therefore important. Inspired by the tunable coupling of the pigment cells and iridocytes in squid skin, we simulated a design for the tunable coupling of a grating and hyperbolic material. This composite metamaterial possessed thermoregulatory properties. The tiny mechanical action (∼250 nm) can tune the solar absorptive quality from 0.9 to 0.03 while keeping the radiative quality small. Our findings could have applications in dynamic and simply controlled thermoregulatory systems for outdoor structures and other technologies that regulate solar infrared absorption.

Nonconventional luminophores devoid of remarkable conjugates have attracted considerable attention due to their unique luminescence behaviors, updated luminescence mechanism of organics and promising applications in optoelectronic, biological and medical fields. Unlike classic luminogens consisting of molecular segments with greatly extended electron delocalization, these unorthodox luminophores generally possess nonconjugated structures based on subgroups such as ether (-O-), hydroxyl (-OH), halogens, carbonyl (CO), carboxyl (-COOH), cyano (CN), thioether (-S-), sulfoxide (SO), sulfone (OSO), phosphate, and aliphatic amine, as well as their grouped functionalities like amide, imide, anhydride and ureido. They can exhibit intriguing intrinsic luminescence, generally featuring concentration-enhanced emission, aggregation-induced emission, excitation-dependent luminescence and prevailing phosphorescence. Herein, we review the recent progress in exploring these nonconventional luminophores and discuss the current challenges and future perspectives. Notably, different mechanisms are reviewed and the clustering-triggered emission (CTE) mechanism is highlighted, which emphasizes the clustering of the above mentioned electron rich moieties and consequent electron delocalization along with conformation rigidification. The CTE mechanism seems widely applicable for diversified natural, synthetic and supramolecular systems.

In recent years, solar interfacial evaporation has been one of the most promising techniques to alleviate freshwater scarcity. However, the salt deposition on the evaporation surface limits the long-term operation of evaporators. Herein, inspired by the salt dilution and secretion mechanisms in halophytes, a solar evaporator with a bundle-cross-layer structured absorber and salt secretion bundles is reported. The unique bundle-cross-layer structure realizes the salt dilution by enhancing the water storage and transport, which enables the absorber to show a high and stable evaporation efficiency of 90.2% over 60 h in brine. More importantly, the salt secretion bundles can completely separate salt crystallization from the absorber by a humidity-controlled salt creeping mechanism. The solar desalination prototype equipped with this evaporator exhibited a stable water collection rate over 600 h of continuous operation, realizing zero liquid discharge in desalination. The study provides new insights into the solar evaporator design and advances other applications such as sea-salt extraction, wastewater treatment, and resource recovery.

Hydrogen, a clean and renewable energy carrier, is a promising alternative energy resource to replace fossil fuels. Among various hydrogen production methods, water electrolysis is a sustainable approach to gain pure hydrogen in useful amounts, but its use is still limited by the lack of efficient and low-cost electrocatalysts. Here, a convenient and straightforward mechanical alloying (MA) process is reported that can be used to produce heterostructured catalysts with good performance for the hydrogen evolution reaction (HER). A NiTiO3/Ni hybrid was reconstructed, which was always considered to be an average HER catalyst, via the ball milling of TiO2 with Ni powder in a vacuum. The resulting material exhibits an ultra-low overpotential of ∼10 mV at 10 mA cm−2 (η10) with a Tafel slope of ∼31 mV dec−1, and maintains its stability after running for 200 h in 1 M KOH. In addition, catalysts produced by directly ball milling NiTiO3 with Ni, Co, or Fe powder also delivered high performance with η10 values of ∼13 mV, 27 mV, and 50 mV, respectively. The enhanced properties are attributed to the introduction of oxygen vacancies into NiTiO3 and the heterostructures produced via MA, which fully utilize the potential of NiTiO3 to accelerate water dissociation for the HER in basic media. Because MA is a mature industrial technique, this approach is promising for large-scale applications. The versatile strategy might also benefit and promote the exploration of catalysts for use in other important electrocatalytic fields.

The energy consumption of outdoor structures, such as automobiles and buildings, has significantly contributed to the problem of energy shortage and global warming. Photonic thermal management plays a crucial role in the thermal behavior of outdoor energy consumption by the functions of solar heating and radiative cooling. Here, we provide a conceptive design of self-adaptive photonic thermal management by tunable radiative cooling and solar heating, which are determined by the absorption spectra of the atmospheric window range and solar energy. These absorption spectra can be tuned by a large cross resonator and a small cross resonator independently, while the compound metasurface of the large and small cross resonators can realize self-adaptive radiative cooling and solar heating in one system. The result shows that the compound metasurface can remain cool at 35 °C and remain warm at 25 °C. These results lead to better designs by photonic thermal management for an outdoor structure.

Nonconventional luminophores without significant conjugations generally possess excitation-dependent photoluminescence (PL) owing to the coexistence of diverse clustered chromophores, which strongly implies the possibility of achieving color-tunable PL and/or persistent room temperature phosphorescence (p-RTP) from their crystals assisted by effective intermolecular interactions. Compared with traditional luminogens, however, nonconventional luminophores generally suffer from poor PL efficiencies. Here, inspired by the highly stable double-helix structure and multiple hydrogen bonds in DNA, we report a series of planar or twisted nonconventional luminophores based on hydantoin (HA), demonstrating unprecedentedly high PL/p-RTP efficiencies and p-RTP lifetimes of up to 87.5%/21.8% and 1.74 s, respectively, accompanying color-tunable p-RTP from sky-blue to yellowish-green. These findings will advance the exploitation of efficient nonconventional luminophores and provide deeper mechanistic insights into the origin of color-tunable p-RTP.

Solar steam generation has attracted increasing attention due to its applications in water purification (e.g., desalination and wastewater treatment). Many strategies have been developed for achieving efficient photothermal conversion materials based on abundant biomass. However, it is challenging for most of these materials to simultaneously facilitate water transport and manage heat well, which results in unsatisfactory evaporation efficiencies under 1 sun illumination. Here, inspired by natural sugarcane stems' bi-functional structures—vascular bundles for mass transport and parenchyma cells for nutrition storage, we use surface-carbonized de-sugaring stems of sugarcane as efficient solar steam generators. The obtained materials have abundant “closed chambers” for thermal insulation (ca. 0.08 W m−1 K−1 in thermal conductivity) and bundles of vertical channels for water transport. These materials achieve an evaporation conversion efficiency up to 87.4% under 1 sun illumination without the usage of additional thermal insulators. This value surpasses all other biomass-derived materials ever reported. Because such bi-functional structures also widely exist in the stems of other Poaceae plants that are renewable and abundant in nature, this strategy is expected to open a new avenue for the future design and fabrication of diverse, more efficient, and cost-effective photothermal-conversion devices.

Vitrimers are a new class of thermosetting polymers that can be thermally processed through bond exchange reactions (BERs) without losing network integrity. In engineering applications, the tunability of their thermomechanical properties is highly desirable to meet the requirements of different working conditions. Here, we report a simple composite-based strategy that avoids complex chemistry to prepare vitrimer blends with tunable thermomechanical properties by virtue of the good weldability of base vitrimers. Effects of processing parameters (such as temperature and time) on the properties of recycled vitrimer blends are experimentally investigated. A computational model that accounts for the random distribution of component vitrimer particles is developed to predict the thermomechanical properties of the recycled vitrimer blends with various compositions. Good agreement is achieved between theoretical prediction and experiment. Parametric studies are further conducted by employing the computational model to explore the designability and provide some basic principles to guide the design of recycled vitrimer blends. Reasonable recyclability of the vitrimer blends is verified by multiple generations of recycling experiments.

Persistent room temperature phosphorescence (p-RTP) of pure organic compounds is drawing much attention due to its unique advantages and promising applications in anticounterfeiting, encryption, bioimaging, etc. Achieving efficient p-RTP, however, remains challenging. In this contribution, we designed and synthesized three benzoic acid–carbazole conjugates, 4-BACZ, 3-BACZ and 2-BACZ, with strong hydrogen bonding and a dimer structure in their crystals. Compared with their ester counterparts, whose highest RTP efficiency (Φp) is 2.6%, these acids exhibit significantly boosted Φp of 6.9%, 3.4% and 2.6% for 4-BACZ, 3-BACZ and 2-BACZ, respectively. Such enhancement should be ascribed to the effective and abundant hydrogen bonding in the crystals, which significantly depressed the vibrational dissipation. This effect is also confirmed by the theoretically calculated much lower reorganization energies. These crystals are also readily fabricated into biocompatible nanoparticles (NPs) with an inherited p-RTP characteristic. Such a p-RTP feature of the crystals and the NPs makes them highly promising for versatile applications. Herein, the application of these materials in anticounterfeiting and high resolution in vivo afterglow bioimaging is demonstrated.

Due to various compositions and morphologies, exquisite intrinsic architectures, and renewability, biomass has been used to generate carbon electrodes for supercapacitors. This review focuses on the latest achievements in the synthesis and application of biomass-derived carbons and composites as supercapacitor electrodes. Particularly, the impact of merits of biomass-derived carbon (high specific surface areas and porosity, doping with different heteroatoms, conductivity, and different nanostructures) on the electrochemical properties of composites is systematically introduced. Thereafter, advances in composites of biomass-derived carbons with graphene, carbon nanotubes, transition metal oxides, and conducting polymers are thoroughly surveyed. Finally, challenges and outlooks towards the future development of biomass-derived carbon materials are discussed.

Deciphering the emission mechanism of nonconventional luminogens and achieving persistent room temperature phosphorescence (p-RTP) from pure organic compounds have drawn increasing attention due to their significant fundamental importance and promising applications. Previous reports on nonconventional luminogens, however, mainly focus on fluorescence, while advances in pure organic p-RTP are generally restricted to aromatic crystals or host–guest systems. Herein, we report the unique intrinsic emission and moreover p-RTP in amorphous nonaromatic polymers of poly(acrylic acid) (PAA), polyacrylamide (PAM) and poly(N-isopropylacrylamide) (PNIPAM). These polymers are nonluminescent in dilute solutions, while being highly emissive in concentrated solutions, nanosuspensions and solid powders/films. This can be rationalized by the clustering-triggered emission (CTE) mechanism, as supported by further thermoresponsive emission, cryogenic and aggregation-induced emission (AIE) experiments, alongside single crystal analysis. Furthermore, PAA and PAM solids under ambient conditions, and PNIPAM solids under vacuum or under nitrogen, demonstrate distinct p-RTP, which can be enhanced through further ionization or pressurization. These results not only refresh our understanding of the emission mechanism of nonaromatic polymers, but also enable the facile fabrication and application of pure organic p-RTP luminogens from readily available compounds, thus providing an important step forward in both nonconventional luminogens and p-RTP.

Due to its fuel-efficient and environmentally friendly nature, the electrocatalytic nitrogen reduction reaction (NRR) has drawn significant attention. However, most of the catalysts reported for the NRR are noble metals or oxides, which are expensive and poorly conductive. Therefore, the development of effective electrocatalysts for nitrogen (N2) fixation under ambient conditions has become a promising field. Herein, we report fluorine-free Ti3C2Tx (T = O, OH) nanosheets with a small size (∼50–100 nm lateral size) as catalysts for the NRR. The as-prepared materials achieved a high NH3 yield (36.9 μg h−1 mgcat−1) and faradaic efficiency (9.1%) at −0.3 V vs. reversible hydrogen electrode (RHE) in 0.1 M HCl. The size effect and fluorine-free properties make the performance around two times higher than that in the case of a fluorine-based treatment. This paper inspires us to pursue the extreme size (e.g. quantum dots) of MXenes which will enhance its NRR property greatly.

Hydrogen peroxide (H2O2) is the main product of enzymatic reactions and plays an important role in biological processes. The detection of H2O2 inside organisms or cells is critical. Here, we report a nickel-iron Prussian blue analogue nanocube doped with molybdenum disulfide and Au nanoparticles (Au@PBA(Ni-Fe):MoS2) as an electrochemical sensing material for the stable detection of H2O2 in neutral solutions for a long time. First, the Prussian blue analogue (PBA(Ni-Fe)) is synthesized by a simple charge-assembly technology, and then etched into PBA(Ni-Fe):MoS2 hollow nanocubes by a high-temperature hydrothermal reaction. Finally, Au nanoparticles are reduced inside the PBA(Ni-Fe):MoS2in situ to generate Au@PBA(Ni-Fe):MoS2 nanocubes. Ni-doping enhances the nanocube's stability in neutral solutions; as a result, the sensor can maintain a stable current response towards H2O2 reduction for more than 1 h. The sensing material can meet the needs of a long-time test. The introduction of Au enhances the electron transfer efficiency, which endows the sensor with good reduction ability for H2O2 at 0 V over a wide linear range (0.5-200 μM and 210-3000 μM) and with a low detection limit (0.23 μM (S/N = 3)), which fulfills the requirements for the detection of H2O2 in a biological system. The sensor can sense H2O2 released from cells stimulated by ascorbic acid. Au@PBA(Ni-Fe):MoS2 provides good guidance for the future development of efficient biosensors to be applied in cell biology.

Fe-N/C single atom catalysts (SACs) exhibit peroxidase-like, oxidase-like, catalase-like, and glutathione peroxidase-like activity. Fe-N/C SACs are successfully applied to control the intracellular H2O2 level. This study not only explores the types of SACs mimicking enzymes but also provides opportunities for SACs in biomedical and other bioengineering applications.

Surface modification for templated synthesis is crucial to achieving three-dimensional (3D) architectured materials for catalysis, photonics, energy storage, etc. However, the existing facile and versatile modification methods (e.g. with dopamine and catechol) generate modification layers that are unstable in harsh environments. These methods are thus unsuitable for electrical applications. Here we report that Ce4+ can act as an effective surface modification reagent for a broad range of substrates (chitinous butterfly wings, carbon paper, nickel foam, and polyethylene terephthalate planks) with various structural features owing to its strong oxidizing ability and Lewis acid nature. The modification yields discrete CeO2 seed layers on substrate surfaces in ca. 0.25-2 h, important for the subsequent conformal growth of CeO2 nanoparticles, Ni(OH)2 nanowires, FeOOH nanosheets, and WO3 nanosheets into 3D architectured materials. The conformally synthesized FeOOH on nickel foam (NF) yields an overpotential of 241 mV at 10 mA cm-1 for an oxygen evolution reaction. This value is comparable to a typical catalyst Ni(Fe)OOH-NF for which the Ni/Fe ratio must be well-optimized. This facile and versatile strategy might have broad applications in the conformal fabrication and application of 3D architectured materials, especially when applied in electrical applications of architectured materials (e.g. Li-ion battery).

Nonconventional luminophores, despite the absence of remarkable conjugations, are attracting increasing attention for their unique intrinsic emission and promising applications. The emission mechanism, nonetheless, remains elusive, which makes rational molecular design difficult. Recently, we proposed the clustering-triggered emission (CTE) mechanism to illustrate the emission. The clustering of nonconventional chromophores with π and n electrons and consequent electron cloud overlap are crucial to the luminescence. Herein, to verify it and to develop new nonconventional luminogens, a sulphur-containing polythioether (P1) was designed and synthesized through the Michael polyaddition. P1 demonstrates bright emission in the aggregates, owing to the clustering of ester groups and sulphur atoms. Furthermore, more efficient emissions are achieved through the oxidation of P1 to polysulfoxide (P2) and polysulfone (P3). Notably, different extents of oxidation also impact on the optimal emission maximum. These results indicate the possibility of fabrication and modulation of the emission of nonconventional luminophores bearing sulphur units.

Nucleic acid amplification methods are increasingly being used to detect trace quantities of DNA in samples for various diagnostic applications. However, quantifying the amount of DNA from such methods often requires time consuming purification, washing or labeling steps. Here, we report a novel microfluidic centrifugation assisted precipitation (μCAP) method for single-step DNA quantification. The method is based on formation of a visible precipitate, which can be quantified, when an intercalating dye (GelRed) is added to the DNA sample and centrifuged for a few seconds. We describe the mechanism leading to the precipitation phenomenon. We utilize centrifugal microfluidics to precisely control the formation of the visible and quantifiable mass. Using a standard CMOS sensor for imaging, we report a detection limit of 45 ng μl-1. Furthermore, using an integrated lab-on-DVD platform we recently developed, the detection limit is lowered to 10 ng μl-1, which is comparable to those of current commercially available instruments for DNA quantification. As a proof of principle, we demonstrate the quantification of LAMP products for a HIV-1B type genome containing plasmid on the lab-on-DVD platform. The simple DNA quantification system could facilitate advanced point of care molecular diagnostics.

Metal oxide gas sensors with porous structures are widely used in numerous applications ranging from health monitoring and medical detection to safety; in this study, we report a highly sensitive SnO2 gas sensor with a multi-level tube/pore structure prepared via biomimetic technology using flax waste as a bio-template and a simple wet chemical process combined with subsequent annealing. Indeed, MLTPS not only maintained and improved the excellence of porous structure gas sensing materials with abundant active sites and large surface-to-volume ratios, but also overcame the deficiency of the lack of gas diffusion channels in porous gas sensing materials. Thus, this novel multi-level tube/pore SnO2 gas sensor exhibited significantly enhanced sensing performance, e.g. an ultra-low response concentration (250 ppb), a high response (87.9), a fast response (9.2 s), a low operating temperature (130 °C) and good stability, for formaldehyde. On the basis of these results, via the reuse of agricultural waste, this study provides a new concept for the low-cost synthesis of environmentally friendly and effective multi-level tube/pore gas sensor materials.

A novel turn-on fluorescent probe (DDND) for highly selective detection of biothiols over other amino acids was synthesized and investigated in this work, which used the 2,4-dinitrobenzenesulfonyl (DNBS) group as a fluorescent quencher. The novel fluorophore (HDM) features a large π-conjugation system and a typical intramolecular charge transfer (ICT) process and has a long emission wavelength at 623 nm as well as a large Stokes shift (λem − λex = 131 nm). Besides that, this red-emitting probe exhibited good linearity ranges with a low detection limit of 0.23 μM for Cys, 0.34 μM for Hcy and 0.41 μM for GSH respectively. Upon titration of thiols, the color of the solution changed from yellow to dark red, which means it can be detected by naked eyes. Finally, probe DDND was successfully applied to bioimage intracellular Cys in HeLa cells with low cytotoxicity.

A novel thermally stable and aggregation-induced emission (AIE) active compound, 2,2'-(([1,1′-biphenyl]-4,4′-diylbis(phenylazanediyl))bis(4,1-phenylene))bis(3,3-diphenylacrylonitrile) (BP2TPAN) was synthesized through a C–N coupling reaction between 2-(4-bromophenyl)-3,3-diphenylacrylonitrile (Br-TPAN) and N,N′-diphenyl-1,4-phenylenediamine, under mild conditions using Pd(OAc)2 and P(t-Bu)3 as a catalyst. The BP2TPAN was characterized by nuclear magnetic resonance spectroscopy, high resolution mass spectrometry and elemental analysis. The thermal analysis showed that the glass transition and decomposition temperatures (5% weight loss) are 96 and 414 °C, respectively. The fluorescent emission peaks changes at 540 and 580 nm upon grinding were attributed to a transformation from crystal to amorphous occurring by altering the condensed state. The photoluminescence quantum yield and fluorescence lifetime of the as prepared and ground samples were 74.3 and 8.4%, 3.4 and 5.1 ns, respectively. The difference of the luminous efficiency of before and after grinding samples indicates BP2TPAN has a high contrast more importantly, both doped and nondoped OLED devices emit different color, the doped one is highly efficient and its Lmax, CEmax, PEmax and EQE are up to 15 070 cd m−2, 11.0 cd A−1, 7.5 lm W−1, and 3.1%, respectively.

Molybdenum disulfide (MoS2) holds great promise as an advanced anode material for lithium ion batteries, but suffers from poor electrochemical performance, especially cycling stability. Here, we report micron-sized particulates composed of encapsulated-type MoS2/C hybrid nanostructures which provide an effective confinement effect to soluble intermediate products during cycling reactions, offering a physically robust framework and locally stable sites for MoS2-based electrode reactions during the cycling process. The micron-sized MoS2/C exhibits a high specific capacity of 1343 mA h g−1 on average at 0.1 A g−1, excellent rate performance (929 mA h g−1 at 1 A g−1), and remarkable cycling stability with 1250 mA h g−1 retention at 1 A g−1 after 480 cycles. In addition, we further clarify the uniform redistribution of S and Mo in the carbon matrix during the decomposition of MoS2 nanoparticles which demonstrates the confinement effect of hybrid structures thus leading to an enhanced electrochemical performance, providing a meaningful suggestion for the rational design of sulfide- and selenide-based carbon hybrid electrodes for practical applications.

An efficient naphthalene-based fluorescent probe (BTNA) for cysteine (Cys) has been rationally designed and synthesized in this work, which consists of a 6-(2-benzothiazolyl)-2-naphthalenol (BNO) fluorophore connected with an acrylate group (the fluorescence quenching and response group). This probe was designed based on a photo induced electron transfer (PET) process and the conjugated addition/cyclization sequence mechanism was employed for Cys detection. It is notable that this novel probe exhibits good linearity ranges with a low detection limit of 0.18 μM for Cys as well as a large stokes shift (λem − λex = 140 nm). Besides these, as a turn-on fluorescent probe, it shows high selectivity and sensitivity for Cys over other amino acids and common ions including the similar structured homocysteine (Hcy) and glutathione (GSH). Finally, the probe BTNA was successfully applied for bioimaging intracellular Cys in living Hela cells with low cytotoxicity.

Nonconventional luminogens without remarkable conjugation have attracted significant attention due to their scientific and technical importance. Their emission mechanism, however, is still under debate. Recently, we proposed the clustering-triggered emission (CTE) mechanism, namely the clustering of nonconventional chromophores and subsequent electron cloud overlap (delocalization) together with simultaneous conformation rigidification, to rationalize the emission. To further check it, nonaromatic polyurethanes (PUs) bearing carbamate (NHCOO) groups were designed and synthesized. While being virtually nonemissive in dilute PU/DMF solutions, PUs are found to be highly emissive when concentrated or aggregated as powders and films. Furthermore, room-temperature phosphorescence (RTP) is detected from the solid powders and films. Clustering of NHCOO groups and electronic communications among carbonyl (CO) units, N and O atoms are accountable for the emission. Such stereoelectronic interactions were also corroborated by the liquid IR (LIR) measurement. In addition, the aggregates of PUs are also useful for explosive detection and cell imaging.

The nano-hole array structure in the black scales of the butterfly can be viewed as a natural solar collector. A low-cost, high-efficiency light absorption structure, inspired by the Papilio ulysses butterfly, was optimized using a finite-difference time-domain method. The results show that the nano-hole structure of Papilio ulysses contributes to light absorption. The shape of the holes affects the angular dependence of absorption. The absorption efficiency was found to be strongly affected by three parameters: H (the depth of the hole), D (the thickness of the hole-wall) and L (the size of the hole). These parameters were swept together in numerous simulations. The optimized nano-hole array saves 84% more material than a thin film of equal absorption (90%) at a wavelength of 600 nm.

Tumor markers are usually over-expressed in human body fluids during the development of cancers. Monitoring tumor markers' level is thus important for early diagnosis and screening of cancers. One way to achieve this is based on the surface enhanced Raman scattering (SERS) technique that can drastically amplify Raman signals of analytes on a plasmonic metal (e.g., Au, Ag, and Cu) surface. However, this promising method suffers from aggregation of plasmonic nanoparticles. Here we report a stable, reproducible, and facile SERS-based readout method to detect an important tumor marker, carcinoembryonic antigen (CEA). This route utilizes Au butterfly wings with natural three dimensional (3D) hierarchical sub-micrometer structures rather than relying on the aggregates of metal nanoparticles. The Au butterfly wings show excellent SERS property and are temperature (80 °C) and time (6 months) stable on a sub-micrometer scale. Thus, the detecting antibodies and enzyme-linked secondary antibodies that are usually applied in conventional enzyme-linked immunosorbent assay (ELISA) can be replaced by chemically synthesized CEA aptamers, significantly simplifying the whole detection process. We demonstrate the feasibility of this method via quantitative detection of clinical CEA level in human body fluids. This work thus demonstrates a promising tumor marker detection technique based on a hierarchical sub-micrometer SERS structure, which could be useful for the mass screening of early stage cancers.

Efficient solar vapor generation under normal one-sun illumination is widely expected to relieve water scarcity all over the world. Herein, we prepare a highly efficient solar vapor generator via the deposition of Ag nanoparticles on diatomite. Ag/diatomite combined with a filter paper, an airlaid paper and a polystyrene foam showed excellent vapor generation performance (the evaporation rate and efficiency (η) were ∼1.39 kg m−2 h−1 and ∼92.2%, respectively) under one-sun illumination at room temperature (25.0 °C). To the best of our knowledge, these values outperform most of the previously reported vapor generation performances and vapor generation efficiencies (if not all). Compared to the performance of Ag/SiO2 (η ≈ 66.2%) and commercial Ag nanoparticles (η ≈ 72.6%), the outstanding performance of Ag/diatomite was attributed to the synergy of the localized surface plasmon resonance (LSPR) effect of Ag nanoparticles and the confinement effect in micrometer size-diatomite. Considering the low cost ($10 per ton) and large-scale availability of diatomite as well as the easy construction of the vapor generation configuration that we proposed, this study provides prospects for practical applications towards relieving water scarcity.

Ge photonic crystals were synthesized by replicating butterfly wings with GeO2 via a facile liquid phase deposition followed by a reducing process. The reflectance spectra of the Ge photonic crystals show a broad peak at wavelengths of 700–800 nm and angle-dependent peak positions.

Hierarchical photonic structures in nature are of special interest because they can be used as templates for fabrication of stimuli-responsive photonic crystals (PCs) with unique structures beyond man-made synthesis. The current stimuli-responsive PCs templated directly from natural PCs showed a very weak external stimuli response and poor durability due to the limitations of natural templates. Herein, we tackle this problem by chemically coating functional polymers, polyacrylamide, on butterfly wing scales which have hierarchical photonic structures. As a result of the combination of the strong water absorption properties of the polyacrylamide and the PC structures of the butterfly wing scales, the designed materials demonstrated excellent humidity responsive properties and a tremendous colour change. The colour change is induced by the refractive index change which is in turn due to the swollen nature of the polymer when the relative humidity changes. The butterfly wing scales also showed an excellent durability which is due to the chemical bonds formed between the polymer and wing scales. The synthesis strategy provides an avenue for the promising applications of stimuli-responsive PCs with hierarchical structures.