Search

A [Si4S10] supertetrahedra containing infrared nonlinear optical material, Rb2CdSi4S10, with a wide band gap (4.23 eV), high LIDT (5 × AgGaS2), and moderate SHG response (0.6 × AgGaS2) is designed and fabricated using a flux method.

l-methionine sulfoxide (Met(O)–OH) as a CPA for cell cryopreservation.

RuCu NFs was synthesized by a facile solvothermal method, showing outstanding HER activity with the low overpotential of 55 mV at 10 mA cm−2.

Anisotropic and super-strong conductive hydrogels were prepared by mechanical stretching combined with the Hofmeister effect. Anisotropic hydrogels exhibit anisotropic mechanical and electrochemical properties.

In this work, we propose hairpin probe-mediated exponential amplification reaction (HEAR) strategy that combines DNA strand displacement with “who triggers, who gets generated” mode, providing single-base discrimination and reduced background signal.

Lattice engineering is a powerful strategy not only to optimize electrocatalytic performances, but also to deepen the understanding of electrocatalytic mechanisms. Lattice engineering can be effectively achieved in core-shell nanocrystals...

3-Amino-4-amidoximinofurazan (AAOF) is an important precursor for the synthesis of high energy furazan energetic materials.

PtRu/C is a well-known commercial electrocatalyst with promising performance for the methanol oxidation reaction (MOR). Further improving the MOR properties of PtRu-based electrocatalysts is highly desirable, especially through structure design. Here we report a facile approach for the synthesis of PdPtRu nanocages with different components through a seed-mediated approach followed by chemical etching. The Pd@PtRu nanocubes were first generated using Pd nanocubes as the seeds and some Pd atoms were subsequently etched away, leading to the nanocages. When evaluated as electrocatalysts for the MOR in acidic media, the PdPtRu nanocages exhibited substantially enhanced catalytic activity and stability relative to commercial Pt/C and PtRu/C. Specifically, PdPt

Pd72Sn28 octopods synthesized through the Stranski–Krastanov growth mode exhibited remarkably enhanced catalytic performance for the EOR relative to commercial Pd/C.

Ultrasmall iridium nanoparticles on reduced graphene oxide (Ir/RGO) exhibited a high NRR activity, attributed to the RGO-induced upshifting of the d-band center for active Ir sites, leading to decreased NRR energy barriers.

Ce-doped Bi2O3 nanosheets were synthesized and exhibited substantially enhanced catalytic selectivity and activity for ECR relative to undoped ones.

High entropy alloys (HEAs) are promising as multifunctional electrocatalysts owing to their inherent compositional and structural complexity and thus the multiple active sites for different reactions.

Reliable and cost-effective quantification of RNA modifications at a specific gene locus is essential to elucidate the pathogenic mechanism encoded by RNA epigenetics. Current methods to quantify N6-methyladenosine (m6A) at specific sites can hardly satisfy the requirement of clinical application because epigenetic information is easily lost through polymerase chain reaction (PCR) assay or other isothermal amplification methods unless tedious pretreatment is applied. Herein, we propose a simple xeno nucleic acid (XNA) as a blocker probe to mediate the methylation specific reverse transcription quantitative polymerase chain reaction (MsRT-qPCR) assay to directly magnify the minor differences between epigenetic bases and unmodified bases in RNA. Strand displacement reactions selectively initiated between the reverse transcription primer (RT-primer) and the XNA probe at the m6A template given the affinity differences between the blocker probes and the m6A-modified RNA (m6A-RNA) and unmodified RNA (A-RNA). Thus, preferential amplification of m6A-RNA was allowed. Integration of a well-established oligo-modified Fe3O4@UiO-66-NH4 allowed purification of mRNA and lncRNA from cellular total RNA samples and greatly reduced the non-specific interference of m6A detection in real samples. Multiple specific sites of m6A in mRNA and lncRNA samples are also successfully quantified. The XNA probe-based m6A assay required only common and available lab equipment and materials, which can be applied in m6A-related fundamental studies and clinical diagnosis.

Ba2BS3Cl and Ba5B2S8Cl2 have been synthesized by using PbCl2 as the flux and source of halogen. The two compounds show 3D network structures built by isolated [BS3] units with different Ba–S–Cl groups. This work enriches the structural diversity of boron chemistry and provides an insight into the synthesis of thioborates.

An intrinsic challenge of the Li metal anode (LMA) that hinders its application is the formation of an unstable solid electrolyte interphase (SEI), which causes uncontrollable Li plating/stripping and deteriorates the cycling stability. While it is desirable to fabricate a robust artificial SEI to stabilize Li, it remains highly challenging to manipulate the composition of the protective film with high precision. Herein, we report a functional ‘gradient coating’ of mechanically enhanced hybrid inorganic–organic polyurea achieved by molecular layer deposition (MLD) for highly stable LMAs. The electrically insulating polymer on the coating surface can confine the electro-deposition of Li and tolerate the volume change due to its good flexibility, while the inner inorganic lithiophilic sites can effectively facilitate and regulate uniform Li nucleation and deposition. Owing to this elaborate interphase design, the protected Li can extend the cycling life significantly at a high current density of 6 mA cm−2. Furthermore, as a proof of concept for application in Li metal batteries (LMBs), stable cycling for over 1500 hours in Li–O2 batteries was achieved. This work demonstrates an innovative nano-scale protective film design for LMAs and creates new opportunities for the realization of high performance next-generation batteries.

Hydrogel-based flexible electronics, especially stretchable human motion sensors, have been intensely investigated in the past few decades. However, challenges remain in the preparation of anti-freezing hydrogels with balanced properties of high sensitivity, large sensing range and suitable mechanical properties in a broad temperature range. In this study, we fabricate a fully-physically crosslinked poly(hydroxyethyl acrylamide)/silk fibroin-LiCl (PHEAA/SF-LiCl) hydrogel with excellent mechanical properties at both room temperature and subzero temperature. Strain sensitivity and durability at both room temperature (25 °C) and low temperature (−30 °C) have been characterized. Strain sensors which can monitor human movements in different situations, including wireless sensing and low temperature sensing have been fabricated, indicating their huge potential in flexible electronics, remote health control and electronic skins.

Herein, a new IR window material CdPbOCl2 is rationally designed and fabricated by a heavy-metal oxide and halide combined strategy. The millimeter-scale CdPbOCl2 single crystal exhibits a wide IR transparent region (1.4–18.0 μm) and excellent comprehensive properties. The results provide an insight into the exploration of broad-band IR window materials.

The key to achieving high efficiencies, high performance, and low costs of adsorption heat pumps/chillers (AHPs/ACs) is to choose a suitable adsorbent. A computational screening of 6013 computation-ready experimental metal–organic frameworks (CoRE-MOFs) is performed for methanol–MOF pairs in AHPs/ACs, and 137 953 hypothetical MOFs (hMOFs) are further directionally screened based on the range of optimal CoRE-MOF descriptors. Compared with the blind screening of CoRE-MOFs (∼13%), ∼80% of hMOFs obtained by the directional screening exhibited high performance in AHPs/ACs, proving the effectiveness of directional screening. Then, the techno-economic analysis (Ctotal) of AHPs/ACs for each MOF was performed based on the equipment cost (Cequipment), cycle cost (Ccycle), and material cost (CMOF). Cequipment accounted for the greatest proportion of Ctotal, but the proportion of Cequipment decreased and the proportion of Ccycle gradually increased as the MOF data set tended to be the materials with better performance. This confirmed the reduction of Ctotal by an effective enhancement of the Ccycle proportion, and that the high manufacturing cost of MOFs would not restrict their widespread use in AHPs/ACs. Among 6 machine learning (ML) algorithms, the random forest could yield the best prediction effect with little effect by the metal type of MOFs, whereas the heat of adsorption and MOF density were two key descriptors to determine Ctotal. 12 lowest-cost CoRE-MOFs and hMOFs were identified for each application, and their average costs in state 2 were only ∼1 USD kJ−1 in AHPs/ACs. Finally, a variant of the well-known MOF (Cu3BTC2) was predicted to possess superior techno-economy, which was confirmed by a parallel methanol adsorption experiment. These comprehensive insights from directional computational screening, ML algorithms to experiment can guide the development of low-cost and high-performance MOFs for AHPs/ACs in a variety of energy conservation and industrial applications.

Pt-based core–shell nanocrystals are a fantastic catalyst to enhance the catalytic performance for the oxygen reduction reaction (ORR). Pursuing further enhancement in ORR properties requires an unconventional interaction between the components of a catalyst. Here Pb is selected to alloy with Pd cores and Pt shells for generating Pd3Pb@PtmPb (m = 3 and 4) nanocubes. Both nanocubes are much more active and stable for the ORR relative to commercial Pt/C, with Pd3Pb@Pt3Pb nanocubes being the better one. Specifically, Pd3Pb@Pt3Pb nanocubes achieved record-breaking mass (4.69 A mgPt−1) and specific (6.69 mA cm−2) activities in alkaline media, which are ∼40.4 and 25.3 times as high as those of commercial Pt/C, respectively. Furthermore, these nanocubes are highly stable with only 9.3% loss in mass activity after 10 000 cycles, as compared to a big decrease of 59.9% for commercial Pt/C. From geometrical phase analysis (GPA) combined with theoretical calculation data, the strain effect in such nanocubes contributes only ∼4% enhancement in ORR activity and the ligand effect is prominent due to the negligible lattice mismatch between Pd3Pb and PtmPb. Besides electronic coupling between Pt and Pd, density functional theory (DFT) calculations show that the strong p–d orbital hybridization between Pt and Pb is critical to downshift the d-band center of Pt and dramatically boost the ORR activity.

A new heavy metal oxychloride, RbPb8O4Cl9, has been synthesized by a high-temperature solution method. The compound crystallizes in the centrosymmetric space group P4/n (no. 85) and exhibits a three-dimensional (3D) framework constructed from [PbO3Cl3], [PbOCl5] and [RbCl8] polyhedra. RbPb8O4Cl9 is an indirect band gap compound with an experimental band gap of 3.66 eV. The first-principles calculations indicate that the band gap mainly originated from the interaction of Pb 6p, O 2p and Cl 2p states. Meanwhile, the calculated birefringence of RbPb8O4Cl9 is about 0.012 at 1064 nm. The compound is the first alkali metal lead oxyhalide, which enriches the structural diversity of oxyhalides and provides an insight for the exploration of new functional materials.

Electrocatalytic CO2 reduction to formate is considered as a perfect route for efficient conversion of the greenhouse gas CO2 to value-added chemicals. However, it still remains a huge challenge to design a catalyst with both high catalytic activity and selectivity for target products. Here we report a unique Sn-doped Bi2O3 nanosheet (NS) electrocatalyst with different atomic percentages of Sn (1.2, 2.5, and 3.8%) prepared by a simple solvothermal method for highly efficient electrochemical reduction of CO2 to formate. Of them, the 2.5% Sn-doped Bi2O3 NSs exhibited the highest faradaic efficiency (FE) of 93.4% with a current density of 24.3 mA cm-2 for formate at -0.97 V in the H-cell and a maximum current density of nearly 50 mA cm-2 was achieved at -1.27 V. The formate FE is stable maintained at over 90% in a wide potential range from -0.87 V to -1.17 V. Electrochemical and density functional theory (DFT) analyses of undoped and Sn doped Bi2O3 NSs indicated that the strong synergistic effect between Sn and Bi is responsible for the enhancement in the adsorption capacity of the OCHO* intermediate, and thus the activity for formate production. In addition, we coupled 2.5% Sn-doped Bi2O3 NSs with a dimensionally stable anode (DSA) to realize battery-driven highly active CO2RR and OER with decent activity and efficiency.

A new fluorine-containing chalcohalide, Ba4GaS4F3, has been synthesized by conventional high-temperature solid-state reaction. The compound crystallizes in the centrosymmetric space group I41/a with a = b = 16.628 (5) A, c = 17.139 (10) A, Z = 16. Experimental and theoretical results confirm that Ba4GaS4F3 is a direct band gap compound with an experimental band gap of about 3.13 eV, and the band gap is mainly determined by the Ba-5p, F-2p and S-3p orbitals. What's more, different from the many newly discovered chalcohalides in the Ba3AM4Q (A = Ga, In; M = S, Se; Q = Cl, Br, I) family, Ba4GaS4F3 is the first reported compound in the Ba4AM4D3 (A = Ga, In; M = chalcogen; D = halogen) family. The results enrich the structural diversity of metal chalcohalides.

Inorganic infrared (IR) second-order nonlinear optical (NLO) crystals have become increasingly important for fulfilling the demands of modern laser technology through frequency conversion via optical parametric oscillation (OPO) and optical parameter amplification (OPA) technology. The AI2BIICIVDVI4 family contains a large number of compounds (to our best knowledge, 102 formula) and shows abundant structural diversity; it could be regarded as a potential source of IR second-order NLO materials with tunable structures and properties. This article summarizes the authors’ contributions to the AI2BIICIVDVI4 family, together with other reported related results where the NLO properties have been provided (a total of 38 compounds). In the title family: (1) the AI site can be occupied by the univalent coinage metals Cu and Ag or the alkali metals Li and Na; (2) the BII site involves divalent metals, including the alkaline earth metals (AEM) Sr and Ba or the d10 metals Zn, Cd, and Hg; (3) the CIV site is prevalently IVA group semi-conducting Si and Ge, or Sn; and (4) the DVI site is S or Se. The structures and optical properties of these compounds are summarized and the influence of substitution at each site on the structures and properties is systematically analyzed.

Recently, flexible and wearable electronics have gained considerable research interest due to their potential applications in wearable devices, energy storage materials, electronic skins, sensors, etc. Compared to elastomers, hydrogels demonstrate more potential for flexible electronics because of their biomimetic structures, suitable mechanical properties and excellent biocompatibility. Among all the designs, nanocomposite hydrogel-based strain and pressure sensors which can transmit external stimulus to electrical signals have been intensely investigated due to their high mechanical strength, considerable conductivity and outstanding sensitivity. Numerous reports have been dedicated to the designs, preparations and applications of nanocomposite hydrogels. This review provides an up-to-date and comprehensive summary of research progresses of nanocomposite hydrogel-based strain and pressure sensors including designing strategies, preparing methods and applications of the five nanofiller based hydrogel sensors including carbon nanotube based, graphene oxide based, MXene based, polymer nanofiller based and other nanofiller based sensors. Representative cases are carefully selected and discussed regarding the fabrication, merits and demerits, respectively. Finally, perspectives and challenges are presented for the designs of future nanocomposite hydrogel-based strain and pressure sensors.

Flexible and stretchable electronics have received tremendous attention for next-generation human-friendly electronic applications. However, fabrication of transparent, fully recyclable and stretchable electronic sensors with low-temperature stability using biocompatible natural polymer-based hydrogels still remains a great challenge. In this study, a green and fully recyclable stretchable electronic sensor with high transparency and ultra-low operating temperature is constructed using ionic conductive gelatin organohydrogels. These gelatin organohydrogels are prepared by a simple strategy of immersing gelatin pre-hydrogels in citrate (Na3Cit) water/glycerol solutions. The existence of Na3Cit in the organohydrogel not only induces the formation of multiple non-covalent cross-linking points, endowing the organohydrogel with high mechanical performances, but also makes the organohydrogel have excellent ionic conductivity. The organohydrogel is also highly transparent and exhibits outstanding antifreezing properties. The mechanical robustness, conductivity and transparency of the organohydrogel can be well maintained even at −60 °C. As a result, a stretchable and transparent electronic sensor based on this organohydrogel is fabricated, which is strain-sensitive with a large linear sensing window and excellent stability. More importantly, the organohydrogel-based electronic sensor can be fully recycled due to the reversible non-covalently crosslinked structure, and the recycled organohydrogel regains its mechanical and sensing properties. The obtained sensors could precisely detect various human activities even below −30 °C, indicating the potential applications of the organohydrogel-based electronic sensor in flexible and stretchable electronics in a broad range of temperature.

Metal–support interaction (MSI) holds great promise for the development of heterogeneous catalysts. Accordingly, it is essential to implement facile methods to modulate MSI for the improvement of catalytic performance. In this study, an effective method is proposed to directly enhance MSI, wherein the electronic properties of Pt are altered by the ion-exchanging reaction of the support, affording incredible catalytic performance. Pt nanoparticles with 1.5 nm diameters are successfully deposited on a quasi-layered sodium titanate support via atomic layer deposition (ALD). The ion-exchanging reaction of the support between the Na-ions and H-ions in acidic media results in the transformation of the support structure, and further modulates the Pt local electronic structure. Such behaviour facilitates the enhancement of MSI offering highly active and stable Pt sites. The as-prepared catalyst exhibits much higher mass activity and long-term stability for the hydrogen evolution reaction (HER) in comparison with Pt/TiO2 and commercial Pt/C. The enhancement mechanism of MSI comes through the structural variation of the support, with modified charge transfer between the Pt and its support. Moreover, this new approach provides a facile and reliable path to develop advanced catalysts with enhanced MSI and motivates further research in many fields.

The development of three-dimensional conductive scaffolds is vital to support the adhesion, proliferation and myocardial differentiation of stem cells in cardiac tissue engineering. Herein, we describe a facile approach for preparing a poly(3,4-ethylenedioxythiophene)/alginate (PEDOT/Alg) porous scaffold with a wide range of desirable properties. In the PEDOT/Alg scaffold, chemically crosslinked alginate networks are formed using adipic acid hydrazide as the crosslinker, and PEDOT is synthesized in situ in the alginate matrix simultaneously. PEDOT exists in the alginate matrix as particles and its morphology can be modulated by adjusting the ratio of PEDOT/alginate. The results also show that the swelling properties, degradation behaviors, mechanical strength and conductivity of the PEDOT/Alg scaffold can be controlled via adjusting the PEDOT/alginate ratio. The introduction of PEDOT can overcome the brittle nature of the pure alginate scaffold. Moreover, the PEDOT/Alg scaffold exhibits excellent conductivity (as high as 6 × 10−2 S cm−1). The introduction of PEDOT improves the protein absorption capacity of the alginate scaffold. To explore its potential application in cardiac tissue engineering, brown adipose-derived stem cells (BADSCs) are seeded in the prepared PEDOT/Alg porous scaffold. The results suggest that the PEDOT/Alg porous scaffold can support the attachment and proliferation of BADSCs. Moreover, it is beneficial for the cardiomyogenic differentiation of BADSCs, especially under electrical stimulation. Overall, we conclude that the PEDOT/Alg porous scaffold may represent an ideal platform to modulate the biological behaviors of BADSCs.

Crystals with both large birefringence and wide transparent range are suitable for broad applications in the areas of optical communications, the laser industry and modulation of the light polarization requirement. In this work, to assist the design of urgently needed crystals with large birefringence in the infrared (IR) region, typical alkali-metal chalcogenides, KPSe6, Na2Ge2Se5, and Li2In2GeSe6 have been studied. They exhibit a hierarchical characteristic in the calculated birefringence by about 0.21, 0.11, and 0.04, respectively. To explore the origin of the birefringence difference, the polarizability anisotropy and the effect of electron distribution anisotropy are analyzed. The alkali-metal chalcogenides KPSe6, Na2Ge2Se5, and Li2In2GeSe6 feature infinite one-dimensional (1D) chains of [PSe6], 2D anionic framework of [Ge2Se5] layers and 3D [In2GeSe9] networks, respectively. It is found that the anionic group with low-dimensional configuration could enhance polarizability anisotropy and render large birefringence for the macroscopic structure. This provides evidence that a low-dimensionality configuration in the structure would be beneficial for the enhancement of optical anisotropy, which can motivate the exploration and design of novel IR birefringent materials.

A metasurface is one of the most effectual platforms for the manipulation of complex optical fields. One of the current challenges in the field is to develop active or reconfigurable functionalities to extend its operation band which is limited by its intrinsic resonant nature. Here we demonstrate a kind of active Fano-resonant asymmetric metasurface in the near-infrared (NIR) region with heterostructures made of a layer of asymmetric split-ring resonators and a thin layer of phase-change material (PCM). In the asymmetric metasurface, significant tunability in the frequency, Q-factor and strength of the Fano resonance are all achieved by precisely controlling the phase transition of the contained PCM Ge2Sb2Te5 (GST), together with changing the geometric asymmetry of the split-ring resonators. Moreover, we provide a complete transition process of the optical properties for GST and an optimized modulation on the active Fano-resonant metasurface. Our approach to dynamically control a Fano-resonant metasurface paves the way to realizing various active photonic meta-devices involving PCM.

Here, we report a facile irradiation-assisted route to fabricate sub-10 nm Ag nanowires from oxide supports using a TEM. The obtained Ag nanowires show a tunable length/diameter aspect ratio with a minimum diameter of about 9.5 nm. Moreover, the nucleation and growth dynamics of Ag nanowires were uncovered from TEM observations.

Due to higher energy density, high-voltage all-solid-state lithium batteries (ASSLBs) have attracted increasing attention. However, they require solid-state electrolytes (SSEs) with wide electrochemical stability windows (ESW, typically >4.2 V) and high-stability against the Li anode. Nevertheless, poly(ethylene oxide) (PEO), the most widely used solid polymer electrolyte (SPE), can’t tolerate a high-voltage over 4 V. Whether the main chain (–C–O–C–) or the terminal hydroxide group (–OH) is the limiting factor for the narrow ESW remains unknown. Herein, poly(ethylene glycol) (PEG) and poly(ethylene glycol)dimethyl ether (PEGDME) with different terminal groups are selected to answer this question. The results show that the reactive terminal –OH group is the limiting factor towards applicability against high voltage and the Li anode. Replacing –OH with more stable –OCH3 can significantly extend the ESW from 4.05 to 4.3 V, while improving the Li-anode compatibility as well (Li–Li symmetric cells stably run for 2500 h at 0.2 mA cm−2). Its practical application is further proved by developing PEGDME-based ASSLB pouch cells. The 0.53 mA cm−2 Li–LiFePO4 and 0.47 mA h cm−2 Li–LiNi0.5Mn0.3Co0.2O2 cells demonstrated high capacity retention of 97% and 90% after 210 cycles and 110 cycles, respectively. This work offers a new strategy for PEO-based high-voltage ASSLB development by changing the unstable terminal groups.

Toehold-mediated strand displacement (TMSD) as an important player in DNA nanotechnology has been widely utilized for engineering non-enzymatic molecular circuits. However, these circuits suffer from uncontrollable leakage and unsatisfactory response speed. We utilized site-specific and sequence-independent nucleases to engineer high- robustness DNA molecular circuits. First, we found that the kinetics of the APE1-catalyzed reaction is highly dependent on substrate stability, allowing for the elimination of asymptotic leakage of DNA split circuits. Second, we obtained strict substrate preference of λ exonuclease (λexo) by optimizing the reaction conditions. Robust single-layer and cascade gates with leak resistance were established by using λ exo. Owing to the remarkably fast kinetics of these nucleases, all the circuits yield a high speed of computation. Compared to TMSD-based approaches, nuclease-powered circuits render advanced features such as leakage resistance, hundreds of times higher speed, and simplified structures, representing a class of promising artificial molecule systems.

Perovskite photodetectors, with the merits of excellent light absorption, high carrier mobility and fast light response, are attracting tremendous interest for their promising application in optical communication, sensing and imaging. However, the requirement of a power supply for photoconductive detectors or the usage of expensive charge transport layers for photovoltaic detectors will pronouncedly increase the whole costs and process complexity. Herein, we demonstrate a self-powered inorganic perovskite photodetector with a novel and simplified configuration of ITO/CsPbBr3/Ag. Since no electron and hole transport layers are employed, it is highly necessary for the CsPbBr3 layer to prevent direct contact between the anode and cathode. Hence, we develop a sequential evaporation technique to fabricate a high-quality CsPbBr3 photosensitive film, which is more controllable than the traditional solution-processing route. The evaporated CsPbBr3 film obtains a much higher crystallinity, phase-purity, coverage and light harvesting capability than the conventionally solution-processed counterparts. The evaporated CsPbBr3 also exhibits larger grain sizes with fewer grain boundaries, enabling a faster charge transport and shorter photoresponse time of 54 ms for the photodetectors. After modification by a thin polymethyl methacrylate (PMMA) layer, the trap states and leakage current pathways in the CsPbBr3 film are substantially decreased, yielding an improved carrier lifetime and suppressed recombination loss. The PMMA-modified photodetectors achieve an ultrafast response time of 3.8 μs and an ultrahigh on/off ratio of 3.5 × 104, which are the best performance among all the reported charge-transport-layer-free perovskite photodetectors and surpass most of the perovskite photodetectors even with charge transport layers. The as-fabricated CsPbBr3 detectors also present superior stability after being stored in ambient air for over 1000 h. Moreover, our devices are successfully applied in a home-made visible light communication system as light receivers to transmit audio signals. Our work solves the contradiction between high detection performance and structure simplification, promoting practical applications of cost-effective, ultrafast and stable inorganic perovskite photodetectors in the optoelectronic field.

Developing high-performance non-Pt electrocatalysts toward the oxygen reduction reaction (ORR) is highly desirable but still challenging for industrial application in fuel cells. Here, we report a facile approach for the synthesis of Au-doped Pd3Pb wavy nanowires (WNWs) with different amounts of Au. We found that the oriented attachment dictated the formation of the WNWs. Such WNWs with several attractive features including a high density of defects, anisotropic one-dimensional nanostructures, ordered intermetallic structures, and Au doping exhibited substantially enhanced catalytic properties in terms of activity and durability towards the ORR in alkaline media compared to commercial Pt/C. Interestingly, the Au doped Pd3Pb WNWs showed a volcano-like relationship in ORR activity as a function of the amount of Au with the 2% Au-doped Pd3Pb WNWs being the best ORR electrocatalysts. Specifically, the 2% Au doped Pd3Pb WNWs achieved the highest mass activity (0.75 mA μg−1) at 0.9 V, which was 1.25 and 7.5 times higher than that of the Pd3Pb WNWs and commercial Pt/C, respectively. More importantly, the 2% Au-doped Pd3Pb WNWs displayed higher durability with only 22.7% loss in mass activity after 10 000 cycles compared to the commercial Pt/C (38% loss in mass activity) due to their chemically stable intermetallic structures and the effect of Au doping.

The assembly of protein-inorganic nanoparticles is an important yet challenging approach that is utilized to develop functional materials in numerous areas, such as bio-catalysis, drug delivery, and biosensing. In this study, we report on a facile, photo-inducible self-assembly method to generate protein-inorganic hybrid nanoplatforms. More specifically, photo-treated disulfide bond rich proteins of lysozyme (LYS) were able to be used as host materials in order to encapsulate nanoparticles (i.e., as-synthesized hydrophobic NIR quantum dots (QDs)) and anti-cancer small molecule drugs (i.e., paclitaxel (PTX)), constructing functional theranostic protein-inorganic hybrid nanoparticles. The modification of the functional polymer of cRGD-PEG contributes to the active tumour targeting characteristic of this protein-inorganic nanocarrier. This novel PTX loaded protein-inorganic hybrid nanoplatform showed high tumour homing accumulation as well as effective tumour inhibition. We believe that this general approach represents a new direction for the development of a photo-induced assembly of protein-inorganic nanoparticles towards versatile applications in both materials science and biomedical fields.

A comprehensive investigation on local structures in iron melts and their role in nucleation under various cooling rates was performed by means of large-scale molecular dynamics simulations. The embedded atoms method (EAM) was adopted to describe the interactions between iron atoms. Connections between short-range order (SRO), medium-range order (MRO), and crystalline nucleation from iron melts were constructed using several structural analysis techniques, including the radial distribution function, common neighbor analysis method, the Voronoi tessellation, and bond order analysis. The simulation results showed that abundant types of atomic clusters with SRO, mainly including the icosahedral-like (ICO-like) and fcc-like clusters, were predominant in undercooled iron melts. The obtained microstructures were determined by the competition between the ICO-like and crystal-like configurations. There existed a critical cooling rate, below which the fcc-like configurations gain the advantage upon cooling and where crystallization could take place; otherwise, the ICO-like configurations are favored and the glass phases could be obtained. Furthermore, it was proved that the crystal nucleation could be divided into three stages: first, a fluctuation and competition between crystal-like and ICO-like clusters in undercooled melts; second, the formation and growth of MRO clusters via the transformation of atomic configurations from ICO-like to crystal-like; finally, the nucleation of bcc nuclei from the core of steady MRO clusters. This process agrees with the Ostwald's step rule and the findings from other investigations. Based on the analysis of the compositional origin of MRO clusters, we further found that the MRO clusters were mainly composed of fcc-like instead of ICO-like configurations, indicating a negative role of ICO-like configurations in crystal nucleation.

Although tremendous efforts have been devoted to exploring non-Pt based electrocatalysts toward the oxygen reduction reaction (ORR), achievements in both catalytic activity and durability are still far from satisfactory. Here, we report a facile approach for the synthesis of intermetallic Pd3Pb ultrathin nanoplate-constructed flowers. Such highly opened hierarchical nanostructures with an ordered phase and low-coordinated edge sites exhibited a substantially enhanced activity toward the ORR. Especially, the intermetallic Pd3Pb nanoflowers achieved a record-breaking mass activity (1.14 mA μgPd−1) in an alkaline solution at 0.9 V vs. a reversible hydrogen electrode among the reported Pd-based ORR electrocatalysts to date, which was 1.8, 3.9 and 11.4 times higher than those of intermetallic Pd3Pb nanocubes, Pd3Pb dendrites and commercial Pt/C, respectively. More importantly, the intermetallic Pd3Pb nanoflowers also showed a higher durability with only 23.7% loss in mass activity after 10 000 cycles compared to the commercial Pt/C (35% loss in mass activity) due to their chemically stable intermetallic structures.

We report a large electrocaloric effect with an adiabatic temperature change (ΔT) of 0.47 K under 20 kV cm−1 combined with a broad temperature span (Tspan) of 23 K within 90% ΔT (maximum) attenuation in a (Ba0.87Ca0.13)(Ti0.87Hf0.13)O3 ceramic by indirect measurement. Here, in this (Ba0.87Ca0.13)(Ti0.87Hf0.13)O3 ceramic, Ca2+ and Hf4+ are introduced into BaTiO3 to obtain a multiphase coexisting region with a diffuse phase transition character. The large electrocaloric effect benefits from a larger number of possible equilibrium orientations of polar states due to multiphase coexistence, and the broad temperature span comes from the diffuse phase transition character. Compared to the control sample, BaTi0.82Hf0.18O3 with only diffuse transition but no multiphase coexistence, (Ba0.87Ca0.13)(Ti0.87Hf0.13)O3 displays a ΔT value nearly 1.5 times larger than that of BaTi0.82Hf0.18O3 (ΔT ∼ 0.33 K), although they exhibit similar Tspan values. Our work may shed light on developing high performance electrocaloric materials with broad temperature ranges.

Developing stable nanocatalysts with high activity for the oxygen reduction reaction (ORR) remains a great challenge in the field of clean energy. Herein, a highly stable and active nanocatalyst is designed by an efficient dealloying of Pt–Ni nanowires in an oxygen saturated solution. It is found that Ni atoms can be removed almost completely in an oxygen atmosphere (D-O2–Pt NWs) instead of an Ar environment, confirmed by a combination of X-ray diffraction, X-ray photoelectron spectroscopy and surface-sensitive electrochemical characterization methods. As a result, the D-O2–Pt NWs exhibit an enhanced mass (0.86 A mgPt−1) and specific (0.99 mA cmPt−2) activity compared to commercial Pt/C for the ORR by a factor of 5 and 5.8, respectively. These catalysts also show an increased power density (30%) and polarization current density (50%) at 0.5 V of real H2/air PEMFCs with respect to commercial Pt/C. In addition, in contrast to the 60% activity loss of Pt/C after accelerated degradation tests (ADTs) for 50 000 potential cycles, the D-O2–Pt NWs show an extremely stable behavior with only 17% performance loss. The high activity and extreme stability of D-O2–Pt NWs are rationalized by the structural effects, confirmed by the combination of quantitative analysis using X-ray absorption fine structure (XAFS), high resolution-transmission electron microscopy (HR-TEM) and average adsorbed CO oxidation potential (μCO1). This work illustrates a new class of Pt based nanocatalysts with high activity and stability for the ORR.

H- and Nb-doped ZnO (HNZO) thin films were fabricated on glass substrates with radio frequency magnetron sputtering. The effect of the flow rate of H2 has been investigated by analyzing the structural, optical, and electrical properties. The incorporation of H during the deposition of Nb-incorporated ZnO films significantly improved their crystallinity, conductivity, and transmittance. The crystallites of the HNZO films were preferentially oriented in the c-axis direction; the films possess high transmittance (approximately 85%) in the visible and near-infrared regions (400 to 1400 nm). The lowest room-temperature resistivity of the HNZO films was measured as 1.28 × 10−3 Ω cm. Such optical and electrical properties along with the remarkable chemical stability of the HNZO films make them a promising candidate for applications in solar cells.

A cost-effective shale gas produced water (PW) treatment plant is an essential facility for safe wastewater management in the shale gas field in the Eastern Sichuan Basin, which is the first commercial shale gas field in China. However, knowledge on PW characteristics and disposal features of this developing shale gas field is limited. This study evaluated the feasibility of pollutant removal from PW in the Eastern Sichuan Basin by a sequential physicochemical process through laboratory and on-site pilot-scale experiments. The results indicated that the CODCr, ammonia nitrogen, total nitrogen, and total phosphorus in the PW are efficiently removed by Fenton–NaClO oxidation, multi-media filtration, and reverse osmosis (RO) processes. A novel recycling route was introduced to rationally dispose the RO concentrate, which was recycled as a raw brine material for a chlor-alkali enterprise through a physicochemical advanced treatment process. A laboratory-scale co-treatment of PW with domestic wastewater was also conducted. Salinity fluctuation, chemical pre-treatment toxicity, resistance, and resilience of the bioreactor after fluctuations may heavily influence the planning, design, and construction of a PW treatment plant, although a coupled chemical–biological process for treating PW is a potential cost-effective management technique. Overall, the sequential physicochemical process that includes RO is a feasible process for the cost-effective treatment of PW from the shale gas field in the Eastern Sichuan Basin. The recycling of the RO concentrate as a raw brine material for the chlor-alkali enterprise is a potential and novel resource recycling mode. The detailed results derived from this study will be considered as a reference for developing the first full-scale centralized shale gas PW treatment plant in this field.

A highly sensitive enzyme-free amplification assay for the detection of apurinic/apyrimidinic endonuclease 1 activity was developed. By incorporating biodegradable MnO2 nanosheets, in situ light up intracellular APE 1 activity was achieved.

Silicon nanotube anodes are notably promising for high-performance lithium-ion batteries due to their outstanding structural stability, but fundamental understanding about their structural evolution during lithiation still remains unclear. Here, the expansion and fracture behavior of lithiated silicon nanotubes is investigated, and the influences of the crystal phase, crystal orientation, inner radius, wall thickness, and thickness–radius ratio are demonstrated. Experiments and simulations demonstrate anisotropic expansion and outer-surface fractures of crystalline silicon nanotubes and isotropic expansion of amorphous ones. The inner holes of nanotubes undergo much less expansion than the outside. The fracture ratio and the maximum hoop stress are positively correlated with both wall thickness and inner radius for crystalline silicon nanotubes. Their competition gives rise to an optimal thickness–outer radius ratio of about 2/3, and the critical diameter reaches 700 nm correspondingly. This research provides significant insight into the lithiation behavior of silicon nanotubes, which could help to design improved silicon anodes.

Ba4(BS3S)2S4 with unprecedented [BS3-S] and [S4] units has been synthesized successfully. The [BS3-S] unit named as (disulfido)bis(sulfido)borate(3-) is composed of a planar [BS3] group with a non-polar covalent S–S bond and stabilized by a large π-conjugation structure. The [S4] unit, formed by four S atoms, shows a helix chain-like structure. This work will enrich the structural diversity of boron chemistry.

S–S bonds in organodisulfides can break and obtain Li+ and e− in the discharge of lithium batteries. Organodisulfides provide precise lithiation sites, and therefore are valuable models for the study of redox reactions in lithium batteries. To understand their electrochemical behavior, we investigate three disulfides with different N-containing heterocycles including 2,2′-dipyridyl disulfide (2,2′-DpyDS), 4,4′-dipyridyl disulfide (4,4′-DpyDS), and 2,2′-dipyridyl disulfide-N,N′-dioxide (DpyDSDO). The three disulfides all show higher discharge voltage plateaus due to the electron-withdrawing groups: DPDS (2.20 V) < 2,2′-DpyDS (2.45 V) = 4,4′-DpyDS (2.45 V) < DpyDSDO (2.80 V). In particular, 2,2′-DpyDS exhibits an outstanding 69% capacity retention over 500 cycles. Our theoretical simulations show that lithium pyridine-2-thiolate, the discharge product of 2,2′-DpyDS, forms compact clusters via N⋯Li⋯S bridges coordinated by lithium ions, which can help reduce its dissolution in liquid electrolyte, and therefore increase the cycle life. Liquid chromatography-mass spectrometry is demonstrated to be a powerful tool for the investigation of discharge/recharge products of soluble organodisulfides in rechargeable lithium batteries.

Uncovering kinetic pathways of non-classical multistep nucleation at the atomic-scale is critical for understanding the complex microscopic mechanism of heterogeneous nucleation and crystallization. However, due to the intricacies in tackling such challenging topics experimentally, the structure of intermediate states and the temperature dependent effect on multistep nucleation at the atomic-scale are still not fully understood. Here, we conduct direct in situ atomic-scale observations of kinetic processes of interfacial multistep nucleation pathways using an aberration-corrected TEM. We provide direct evidence for temperature-dependent multistep nucleation pathways in a supported bismuth system at the atomic-scale: a droplet-crystal two-step nucleation pathway at high temperature close to the melting point of bulk bismuth, a droplet-local ordered structure-crystal three-step nucleation pathway at medium temperature between a critical temperature Tc1 and the lowest size-dependent melting temperature of bismuth nanoparticles, and a cluster-crystal two-step nucleation pathway at a temperature lower than the lowest melting point (Tl). The related critical temperature Tc1 and the lowest melting point in the three pathways are confirmed based on the size-dependent melting phase diagram of Bi nanoparticles. Statistical analyses imply that the nucleation pathway plays an important role in deciding the nucleation and crystallinity kinetics, and the critical size of crystal nucleation is controlled by temperature. The understanding of multiple intermediate steps in nucleation and the temperature effect on nucleation pathways has important implications for the synthesis and growth of clusters, amorphous and crystalline materials, and these findings may further enrich the nucleation theory.

Hydrolysis of ammonia borane (AB) is a safe and convenient means of H2 production when efficient catalysts are used. Here we report a facile one-pot solvothermal method to synthesize Rh/WO3−x hybrid nanowires. Ultra-small Rh nanoparticles with an average size of ∼1.7 nm were tightly anchored on WO3−x nanowires. Rh/WO3−x catalysts exhibited substantially enhanced activity for hydrolytic dehydrogenation of AB under both dark and visible light irradiation conditions relative to mixed Rh nanoparticles and WO3−x nanowires (Rh + WO3−x), and Rh/C and WO3−x nanowires. X-ray photoelectron spectroscopy (XPS) analysis indicated that the synergistic effect between Rh nanoparticles and WO3−x nanowires was responsible for such an enhancement in activity. Specifically, Rh/WO3−x achieved the highest turnover frequency (TOF) with a value of 805.0 molH2 molRh−1 min−1 at room temperature under visible light irradiation. The H2 release rate as a function of reaction time exhibited a volcano plot under visible light irradiation, indicating that a self-activation process occurred in the hydrolytic dehydrogenation of AB due to additional oxygen vacancies arising from in situ reduction of WO3−x nanowires by AB, and thus an enhanced localized surface plasmon resonance (LSPR). Such a self-activation process was responsible for the enhanced catalytic activity under visible light irradiation relative to that under dark conditions, which was supported by the lower activation energy (45.2 vs. 50.5 kJ mol−1). In addition, Rh/WO3−x catalysts were relatively stable with only little loss in activity after five cycles due to the tight attachment between two components.

In this study, nano-hydroxyapatite crystals (nHAs) were prepared in the presence of zwitterionic poly(3-carboxy-N,N-dimethyl-N-(3′-acrylamidopropyl) propanaminium inner salt) (PCBAA) at different concentrations and pH microenvironments, denoted as Z-nHAs. The phase, morphology, size of apatite, and interactions between nHAs and PCBAA were systemically characterized via XRD, TEM, FTIR, and TGA. The results showed that Z-nHAs could be formed at all pH ranges in the presence of PCBAA in our experiment. It was different from the case of pure nHAs that could not be formed under an acidic microenvironment without PCBAA. In addition, a higher pH value was beneficial for the formation of nHAs with a smaller size. Z-nHAs exhibited a fiber-like structure at the initial 2 h and became rod-like in shape after 5 h, whereas pure nHAs prepared in water had an irregular flake-like structure. Moreover, 14–20% PCBAA could be incorporated into Z-nHAs via interactions between the quaternary ammonium group (–R3N+) and carboxyl group (–COO−) in the PCBAA chain and Ca2+/PO43− of nHA. A possible mechanism for the formation of Z-nHAs in the presence of PCBAA was proposed based on the experimental results.

Microstructural engineering is an effective approach to improving electrocatalytic activity of a catalyst. Shape-controlled hollow nanostructures represent a class of interesting architectures for use in electrocatalysis, given that they may offer large surface area, preferably exposed active sites, reduced diffusion pathways for both charge and mass transport, as well as enhanced catalytic activity due to the nano-cavity effect. Herein, we for the first time report the synthesis of hollow cobalt phosphide nanoparticles with a well-defined octahedral shape (CoP OCHs) via multi-step reactions. When used as pre-catalysts for the oxygen evolution reaction (OER) in an alkaline solution, the as-obtained CoP OCHs not only show high apparent catalytic activity requiring an overpotential of only 240 mV to deliver the benchmark current density of 10 mA cm−2, but also exhibit an exceptionally high catalyst surface-area-based turnover frequency (TOF) of 17.6 s−1 and a catalyst mass-based TOF of 0.072 s−1 at a low overpotential of 300 mV, demonstrating excellent intrinsic catalytic activity. Moreover, the CoP OCHs also show high electrocatalytic activity for the methanol oxidation reaction (MOR), outperforming most metal phosphide based MOR catalysts reported so far. The synthetic strategy reported here can be readily extended to prepare other hollow shape-controlled metal phosphide catalysts.

In this article, we for the first time report the synthesis and electrocatalytic properties of ruthenium cobalt phosphide hybrid clusters for the hydrogen evolution reaction (HER). Two types of catalysts are investigated: wet chemical reduction of Ru3+ on pre-formed cobalt phosphide (CoP) nanoparticles results in ruthenium–cobalt phosphide side-by-side structures (Ru/CoP); while phosphorizing chemically reduced RuCo alloy leads to the formation of hybrid ruthenium cobalt phosphide (RuCoP) clusters. Compared to pristine Ru clusters, both Ru/CoP and RuCoP show significantly improved HER performance in both acidic and alkaline solutions. In particular, the hybrid RuCoP clusters demonstrate a considerably low overpotential (η10) of 11 mV at −10 mA cm−2 and a high turnover frequency (TOF) of 10.95 s−1 at η = 100 mV in 0.5 M H2SO4. Even in 1.0 M KOH the excellent HER activity of the RuCoP clusters remains, with a very low η10 of 23 mV and exceptionally high TOF value of 7.26 s−1 at η = 100 mV. Moreover, the RuCoP catalysts can sustain galvanostatic electrolysis in both acidic and alkaline solutions at −10 mA cm−2 for 150 h with little degradation, showing better catalytic stability than the state-of-the-art commercial Pt/C catalysts. Our density functional theory (DFT) calculations indicate that the RuCoP hybrid exhibits a hydrogen adsorption energy very close to that of Pt and water and –OH adsorption energies distinct from pristine Ru, which reasonably explain the experimentally observed excellent HER activities and highlight the importance of synergistic coupling with cobalt phosphide to boost the HER performance of ruthenium.