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Rechargeable magnesium batteries (RMBs) hold great potential for large-scale energy storage due to the dendrite-free deposition and high theoretical volumetric capacity of the magnesium anode. However, the sluggish kinetics and poor reversibility of cathodes hinder their development in terms of high capacity and long-term cycling stability. Herein, a confined in situ growth strategy is presented to construct a novel copper sulfide (CuS)/delaminated Ti3C2Tx MXene (d-Ti3C2Tx) heterostructure, where ultrafine CuS nanocrystals are tightly anchored on the d-Ti3C2Tx substrate through S–Ti–C interfacial covalent bonding. Density functional theory (DFT) calculations demonstrate the strong interaction not only enhances the conductivity of CuS, enabling rapid charge transfer, but also effectively maintains structural stability during the charge/discharge process. As a result, the CuS/d-Ti3C2Tx heterojunction exhibited high reversible specific capacity (336.5 mA h g−1) and outstanding rate capability. Remarkably, an impressive long-term cycling performance with a stable capacity of 92.2 mA h g−1 at 1000 mA g−1 was achieved over 1000 cycles. This study demonstrates the feasibility of integrating CuS with d-Ti3C2Tx MXene and provides an avenue for designing high-performance cathode materials for RMBs. [ABSTRACT FROM AUTHOR]

The design and synthesis of cost-effective and stable bifunctional electrocatalysts for water splitting via a green and sustainable fabrication way remain a challenging problem. Herein, a bio-inspired method was used to synthesize NiFeP nanoparticles embedded in (N,P) co-doped carbon with the added carbon nanotubes. The obtained Ni0.8Fe0.2P-C catalyst displayed excellent hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performances in both alkaline and alkaline simulated seawater solutions. The optimal Ni0.8Fe0.2P-C/NF only needs overpotentials of 45 and 242 mV to reach the current density of 10 mA cm−2 under HER and OER working conditions in 1.0 M KOH solution, respectively. First-principles calculations revealed the presence of a strong interaction between the carbon layer and metal phosphide nanoparticles. Benefiting from this and carbon nanotubes modification, the fabricated Ni0.8Fe0.2P-C presents impressive stability, working continuously for 100 h without collapse. A low alkaline cell voltage of 1.56 V for the assembled Ni0.8Fe0.2P-C/NF//Ni0.8Fe0.2P-C/NF electrocatalyzer could afford a current density of 10 mA cm−2. Moreover, when integrated with a photovoltaic device, the bifunctional Ni0.8Fe0.2P-C electrocatalyst demonstrates application potential for sustainable solar-driven water electrolysis. [ABSTRACT FROM AUTHOR]

A pure silica STW zeolite is synthesized with no impurities under a wide range of synthesis conditions with and without fluoride by using easily available 1-methyl-1,5-diazabicyclo[4.3.0]non-5-ene (MDBN) as a template. MDBN having an appropriate size and geometry fits well in the STW cage, leading to its high specificity in structure-directing formation of zeolite STW. [ABSTRACT FROM AUTHOR]

In this work, a designed porous DNA crystal with high intrinsic biocompatibility was used as the scaffold material to load fluorescent guest molecules to detect anti-cancer drugs. It is shown here that the synthesized crystals have the characteristics consistent with the designed large solvent channels, and can therefore accommodate guest molecules such as fluorescent proteins that cannot be accommodated by less porous crystals. Eu(TTA)3phen and Tb(acac)3phen lanthanide complexes were individually noncovalently loaded into the porous crystals, resulting in hybrid luminescent DNA crystals. Emodin, an anti-cancer, anti-tumor, anti-inflammatory drug, was found to quench lanthanide complexes in solution or in crystals. Notably, emodin is the active ingredient of Lianhua Qingwen Capsule, an anti-COVID-19 drug candidate. Therefore, the porous DNA crystals reported here have potential applications as a biocompatible and theranostic delivery biomaterial for functional macromolecules. [ABSTRACT FROM AUTHOR]

SiOx is one of the most promising anode materials for lithium-ion batteries (LIBs), due to its high theoretical capacity and low cost. However, the huge volume expansion and low electron/ion diffusion rate hinder its further commercial applications. Herein, a simple molecular polymerization method is developed to synthesize N,P co-doped SiOx–C composites (denoted as SiOx–C@CNT), in which SiOx and carbon are uniformly dispersed at the atomic level, and the embedded carbon nanotubes improve the lithium ion diffusion kinetics. Benefiting from the unique structure, the SiOx–C@CNT composites exhibit a high reversible capacity of 848 mA h g−1 at 0.1 A g−1 and long cycling stability (84.0% capacity retention after 1500 cycles). More impressively, the LiCoO2∥SiOx–C@CNT full battery also exhibits stable cycle life (only 4.7% capacity loss after 300 cycles at 1 C). These results show the application potential of the SiOx–C@CNT anode in LIBs. [ABSTRACT FROM AUTHOR]

With the ongoing progress in exploring novel fabrication methods, topics towards high-performance, simply fabricated organic light-emitting diodes (OLEDs) have received a great deal of attention. Brush-coating is a superior liquid phase thin film deposition technology with nearly 100% material utilization, which has remarkable potential application in depositing large-area uniform films. Here, a uniform and smooth polymer hole-injection layer and a small molecule light-emitting layer are successfully fabricated through brush-coating by controlling the wetting and dewetting processes. White phosphorescent OLEDs with blue and orange complementary colours are constructed by continuously brush-coating the hole-injection layer and small molecule light-emitting layer. The brush-coated white device possesses a peak luminance of 29 190 cd m−2 and a current efficiency of 29.3 cd A−1, which are comparable to those of the spin-coated device with the same structure. In addition, the brush-coated red, green and blue phosphorescent OLEDs exhibit excellent performance in our research with peak current efficiencies of 16.7, 30.4 and 20.9 cd A−1, respectively. These results demonstrate that the brush-coating technology is a simple and effective strategy for depositing uniform organic films and, consequently, fabricating a high-performance device. What's more, brush-coating is expected to be applied to the best-to-date, large-area, flexible or patterned OLEDs in the future. [ABSTRACT FROM AUTHOR]

Lithium metal has been intensively investigated as a promising anode for next generation rechargeable Li metal batteries (LMBs). However, the safety concern on Li anodes caused by uncontrolled Li dendrite growth in liquid electrolytes hinders their application. Herein, a novel poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) based gel polymer electrolyte (GPE) with an asymmetric structure has been designed and developed to effectively retard the growth of lithium dendrites. Atomistic simulations confirm the strong interactions between PF6− and dipoles in the polymer matrix, which can anchor PF6− in the GPE and slow down its mobility to prevent space charge formation. In addition, this unique asymmetric membrane with a channel upper layer greatly enhances the mobility of Li+ in the GPE due to its low tortuosity and high porosity. The synergistic effect of the ion-dipole interaction and asymmetric structure increases the Li+ transference number to 0.66 and ionic conductivity to 3.36 mS cm−1 (20 °C). Using this superior asymmetric GPE, Li‖Li symmetric cells show more stable cycle performance than those using a liquid electrolyte. Li‖LiFePO4 batteries with the asymmetric GPE also deliver an impressive electrochemical performance, i.e., coulombic efficiency of 99.5% at 2C after 600 cycles. In consequence, this novel asymmetric GPE possesses potential application in high energy LMBs. [ABSTRACT FROM AUTHOR]

The development of rechargeable magnesium ion batteries (MIBs) has received increasing attention due to its low cost, high theoretical volumetric capacities, environmental friendliness and good safety. However, one of the main challenges faced by MIBs is the difficulty in finding a suitable electrode material due to the sluggish kinetics of the magnesium ion. Herein, we report a manganese ion pre-intercalated hydrated vanadium oxide (Mn0.04V2O5·1.17H2O) as the cathode material for MIBs for the first time. Pre-intercalation of Mn2+ leads to excellent structural stability and allows fast (de)insertion of Mg2+ ions. The charge shielding effect of crystal water in the material enhances the Mg2+ (de)insertion kinetics and the unique nanostructure ensures the large contact area and shortens the Mg2+ diffusion distance between the electrode and electrolyte. Benefiting from the structure and charge shielding effect, the Mn0.04V2O5·1.17H2O nanobelts exhibit excellent cycling stability (capacity retention of 82% after 10 000 cycles at 2 A g−1) and superior rate performance. These results indicate that Mn0.04V2O5·1.17H2O is a promising and attractive cathode material for MIBs. [ABSTRACT FROM AUTHOR]

High-loading atomic cobalt (12.8 wt%) dispersed on nitrogen-doped graphene was successfully synthesized via considerably low temperature pyrolysis. The catalyst exhibits excellent electrocatalytic performance towards the oxygen reduction reaction with a large limiting diffusion current density of 5.60 mA cm−2 (10% higher than that of commercial Pt/C), and when acting as the air catalyst of Zn–air batteries, a high open-circuit voltage of ＞1.40 V and excellent power density are also achieved. [ABSTRACT FROM AUTHOR]

One-dimensional porous Co3O4 nanowires are successfully prepared by thermal decomposition of a coordination polymer, using nitrilotriacetic acid (NA) as a chelating agent via a solvothermal method. The Co3O4 nanowires with porous structure comprise numerous nanoparticles and maintain the nanowire structure of Co–NA precursors. When evaluated for supercapacitor electrode materials, Co3O4 nanowires exhibit superior electrochemical properties. A high specific capacitance of 2815.7 F g−1 at 1 A g−1 can be observed with a desirable rate specific capacitance of 765 F g−1 at 20 A g−1. Fortunately, the capacitive behaviors of the obtained porous Co3O4 nanowire electrodes are superior among reported cobalt oxides, and the excellent coulombic efficiency (about 100%) and good cycling property demonstrate high electrochemical stability and tremendous potential for high performance supercapacitors. [ABSTRACT FROM AUTHOR]

The emergence of various single cell separation and identification platforms has greatly promoted the development of single cell research. Among these platforms, microfluidic chip-based strategies occupy a significant position in single cell separation and identification. Here, we proposed a self-priming isometric and Equant screw valve-based microfluidic chip (SIES chip) for high throughput single cell isolation and identification. With several special designs, such as a peripheral water tank to balance negative pressure distribution in a marginal area of the chip, a screw valve to preserve the suction power during the step-by-step sample loading, and multistage branching “T” shape channels to separate cells evenly into the chambers, up to 2000 single cells can be well dispersed and analyzed at the same time using this chip. We applied this chip for the isolation and identification of single A549 cells targeting the activated leukocyte cell adhesion molecule (ALCAM) gene. The results showed that only a small proportion (approximately 5.1%) of A549 cells expressed ALCAM, which can potentially provide a reference for A549 cell reclassification. Besides being inexpensive, user-friendly and portable, our chip can be used in some resource-limited settings and may have a great potential in POC (Point-of-Care) applications. [ABSTRACT FROM AUTHOR]

Novel NASICON-type carbon-coated LiTi2(PO4)3 microflowers (LTP-F/C) as a hybrid magnesium–lithium-ion battery (MLIB) cathode is presented for the first time. Benefiting from the synergistic effect of the NASICON structure, nanosheet-constructed hierarchical architecture, and uniform carbon coating of LTP-F/C, this hybrid MLIB exhibits extraordinary electrochemical performance: ultra-high cycling stability (capacity retention of 80% after 3000 cycles at 10 C) and outstanding rate capability (94 mA h g−1 at 20 C) under a high discharge voltage plateau of ∼1.71 V (vs. Mg/Mg2+). This hybrid battery system design is highly promising for large-scale energy storage applications. [ABSTRACT FROM AUTHOR]

As an absolute quantification method at the single-molecule level, digital PCR has been widely used in many bioresearch fields, such as next generation sequencing, single cell analysis, gene editing detection and so on. However, existing digital PCR methods still have some disadvantages, including high cost, sample loss, and complicated operation. In this work, we develop an exquisite scalable self-priming fractal branching microchannel net digital PCR chip. This chip with a special design inspired by natural fractal-tree systems has an even distribution and 100% compartmentalization of the sample without any sample loss, which is not available in existing chip-based digital PCR methods. A special 10 nm nano-waterproof layer was created to prevent the solution from evaporating. A vacuum pre-packaging method called self-priming reagent introduction is used to passively drive the reagent flow into the microchannel nets, so that this chip can realize sequential reagent loading and isolation within a couple of minutes, which is very suitable for point-of-care detection. When the number of positive microwells stays in the range of 100 to 4000, the relative uncertainty is below 5%, which means that one panel can detect an average of 101 to 15 374 molecules by the Poisson distribution. This chip is proved to have an excellent ability for single molecule detection and quantification of low expression of hHF-MSC stem cell markers. Due to its potential for high throughput, high density, low cost, lack of sample and reagent loss, self-priming even compartmentalization and simple operation, we envision that this device will significantly expand and extend the application range of digital PCR involving rare samples, liquid biopsy detection and point-of-care detection with higher sensitivity and accuracy. [ABSTRACT FROM AUTHOR]

A hollow shell-controlled Li3VO4 is fabricated via a facile self-template method, which has a controllable shell thickness in the range of 10–300 nm. This hollow shell-controlled Li3VO4 composited with reduced graphene oxide exhibits excellent rate capability (201 mA h g−1 at 125 C) and superior high-temperature stability (364.2 mA h g−1 after 1000 cycles at 10 C, 60 °C). [ABSTRACT FROM AUTHOR]

Two types of porous cobalt manganese oxide nanowires (MnCo2O4 and CoMn2O4) with different structures have been successfully synthesized by thermal decomposition of organometallic compounds for the first time. Nitrilotriacetic acid (NA) was used as a chelating agent to coordinate Co(II) and Mn(II) ions in various molar ratios, in a hydrothermal condition. The microstructure of as-synthesized cobalt manganese oxides, composed of numerous nanoparticles, completely retains the 1D network structure of the Co -- Mn -- NA coordination precursors without structure collapse. Electrochemical properties of the cobalt manganese oxide materials have been tested for supercapacitors at room temperature. Both the MnCo2O4 and CoMn2O4 electrodes display the outstanding capacitive behaviors and superior electrochemical properties. The CoMn2O4 nanowire shows excellent capacitance and desirable rate performance (2108 F g-1 at 1 A g-1 and 1191 F g-1 at 20 A g-1) compared to that of the MnCo2O4 nanowire (1342 F g-1 at 1 A g-1 and 988 F g-1 at 20 A g-1). Electrochemical impedance spectra (EIS) results also reconfirm that the CoMn2O4 nanowires display more facile electrolyte diffusion and higher capacitor response frequency than MnCo2O4 nanowires. This can be ascribed to the facile electrolyte/OH- ion penetration and better Faradaic utilization of the electroactive surface sites that generated by the smaller particle size and higher surface area. [ABSTRACT FROM AUTHOR]

An integrated on-chip valve-free and power-free microfluidic digital PCR device is for the first time developed by making use of a novel self-priming compartmentalization and simple dehydration control to realize ‘divide and conquer’ for single DNA molecule detection. The high gas solubility of PDMS is exploited to provide the built-in power of self-priming so that the sample and oil are sequentially sucked into the device to realize sample self-compartmentalization based on surface tension. The lifespan of its self-priming capability was about two weeks tested using an air-tight packaging bottle sealed with a small amount of petroleum jelly, which is significant for a practical platform. The SPC chip contains 5120 independent 5 nL microchambers, allowing the samples to be compartmentalized completely. Using this platform, three different abundances of lung cancer related genes are detected to demonstrate the feasibility and flexibility of the microchip for amplifying a single nucleic acid molecule. For maximal accuracy, within less than 5% of the measurement deviation, the optimal number of positive chambers is between 400 and 1250 evaluated by the Poisson distribution, which means one panel can detect an average of 480 to 4804 template molecules. This device without world-to-chip connections eliminates the constraint of the complex pipeline control, and is an integrated on-chip platform, which would be a significant improvement to digital PCR automation and more user-friendly. [ABSTRACT FROM AUTHOR]

Novel layered Li3V2(PO4)3/rGO&C sheets are synthesized by novel interfacial modified assembly, freeze-drying and confined annealing processes. The uniform LVP layers are alternated with rGO&C layers to form the composite layered structure, providing effective electron and ion transport. As a lithium-ion battery cathode, the composite displays excellent electrochemical performance. [ABSTRACT FROM AUTHOR]

The design and synthesis of cost-effective and stable bifunctional electrocatalysts for water splitting via a green and sustainable fabrication way remain a challenging problem. Herein, a bio-inspired method was used to synthesize NiFeP nanoparticles embedded in (N,P) co-doped carbon with the added carbon nanotubes. The obtained Ni 0.8 Fe 0.2 P-C catalyst displayed excellent hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performances in both alkaline and alkaline simulated seawater solutions. The optimal Ni 0.8 Fe 0.2 P-C/NF only needs overpotentials of 45 and 242 mV to reach the current density of 10 mA cm -2 under HER and OER working conditions in 1.0 M KOH solution, respectively. First-principles calculations revealed the presence of a strong interaction between the carbon layer and metal phosphide nanoparticles. Benefiting from this and carbon nanotubes modification, the fabricated Ni 0.8 Fe 0.2 P-C presents impressive stability, working continuously for 100 h without collapse. A low alkaline cell voltage of 1.56 V for the assembled Ni 0.8 Fe 0.2 P-C/NF//Ni 0.8 Fe 0.2 P-C/NF electrocatalyzer could afford a current density of 10 mA cm -2 . Moreover, when integrated with a photovoltaic device, the bifunctional Ni 0.8 Fe 0.2 P-C electrocatalyst demonstrates application potential for sustainable solar-driven water electrolysis.

In this work, a designed porous DNA crystal with high intrinsic biocompatibility was used as the scaffold material to load fluorescent guest molecules to detect anti-cancer drugs. It is shown here that the synthesized crystals have the characteristics consistent with the designed large solvent channels, and can therefore accommodate guest molecules such as fluorescent proteins that cannot be accommodated by less porous crystals. Eu(TTA) 3 phen and Tb(acac) 3 phen lanthanide complexes were individually noncovalently loaded into the porous crystals, resulting in hybrid luminescent DNA crystals. Emodin, an anti-cancer, anti-tumor, anti-inflammatory drug, was found to quench lanthanide complexes in solution or in crystals. Notably, emodin is the active ingredient of Lianhua Qingwen Capsule, an anti-COVID-19 drug candidate. Therefore, the porous DNA crystals reported here have potential applications as a biocompatible and theranostic delivery biomaterial for functional macromolecules.

SiO x is one of the most promising anode materials for lithium-ion batteries (LIBs), due to its high theoretical capacity and low cost. However, the huge volume expansion and low electron/ion diffusion rate hinder its further commercial applications. Herein, a simple molecular polymerization method is developed to synthesize N,P co-doped SiO x -C composites (denoted as SiO x -C@CNT), in which SiO x and carbon are uniformly dispersed at the atomic level, and the embedded carbon nanotubes improve the lithium ion diffusion kinetics. Benefiting from the unique structure, the SiO x -C@CNT composites exhibit a high reversible capacity of 848 mA h g -1 at 0.1 A g -1 and long cycling stability (84.0% capacity retention after 1500 cycles). More impressively, the LiCoO 2 ∥SiO x -C@CNT full battery also exhibits stable cycle life (only 4.7% capacity loss after 300 cycles at 1 C). These results show the application potential of the SiO x -C@CNT anode in LIBs.

Transition-metal-doping can improve some physical properties of titanium dioxide (TiO 2 ) nanowires (NWs), which leads to important applications in miniature devices. Here, we investigated the elastic moduli of single-crystalline pristine and Fe-doped rutile TiO 2 NWs using the three-point bending method, which is taken as a case study of impacts on the elastic properties of TiO 2 NWs caused by transition-metal-doping. The Young's modulus of the pristine rutile TiO 2 NWs decreases when the cross-sectional area increases (changing from 246 GPa to 93.2 GPa). However, the elastic modulus of the Fe-doped rutile NWs was found to increase with the cross-sectional area (changing from 91.8 GPa to 200 GPa). For NWs with similar geometrical size, the elastic modulus (156.8 GPa) for Fe-doped rutile NWs is 24% smaller than that (194.5 GPa) of the pristine rutile TiO 2 NWs. The vacancies generated by Fe-doping are supposed to cause the reduction of elastic modulus of rutile TiO 2 NWs. This work provides a fundamental understanding of the effects of transition-metal-doping on the elastic properties of TiO 2 NWs., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Novel layered Li3V2(PO4)3/rGO&C sheets are synthesized by novel interfacial modified assembly, freeze-drying and confined annealing processes. The uniform LVP layers are alternated with rGO&C layers to form the composite layered structure, providing effective electron and ion transport. As a lithium-ion battery cathode, the composite displays excellent electrochemical performance.

The effects of NbN nanoparticles synthesized via a simple "urea glass" route on the dehydrogenation properties of LiAlH4 have been systematically investigated. The particle size of the as-synthesized NbN nanoparticles is determined to be about 10 nm. The surface configuration and dehydrogenation behaviors of the 2 mol% NbN-doped LiAlH4 (2% NbN-LiAlH4) system are also discussed. It is found that the 2% NbN-LiAlH4 sample starts to decompose at about 95 °C and releases a total of 7.10 wt% hydrogen, which is 55 °C lower than that of as-milled LiAlH4. The isothermal dehydrogenation kinetics shows that the 2% NbN-LiAlH4 sample could release approximately 6.10 wt% hydrogen in 150 min at 130 °C, whereas as-received LiAlH4 only releases about 0.63 wt% hydrogen under the same conditions, revealing that the enhancements arising upon adding NbN nanoparticles are almost 8-9 times that of as-milled LiAlH4. The activation energy (Ea) is calculated to be 71.91 and 90.87 kJ mol(-1) for the first and second hydrogen desorption of the NbN-LiAlH4 sample, a 38% and 32% reduction relative to as-received LiAlH4, respectively. A detailed modeling study shows that the first dehydrogenation step can be sufficiently interpreted with the nucleation and growth in a one-dimensional model based on the first-order reaction. More interestingly, the dehydrogenated LiAlH4 sample can recharge H2 under a 5.5 MPa hydrogen pressure. An SEM image of the dehydrogenated 8% NbN-LiAlH4 sample after HP-DSC under 5.5 MPa H2 shows that some nanorods appear.

LiCoO(2) material is recovered from spent lithium-ion batteries and investigated as anode materials for Ni/Co power batteries for the first time. LiCoO(2) electrodes with a small amount of S-doping display excellent electrochemical properties. The electrochemical reactions occurring on M0 electrodes during the first several cycles and after being activated are proposed, respectively. A function mechanism of S powder on M10 electrode is also proposed.