Tin-doped NiFe2O4 nanoblocks grown on an iron foil for efficient and stable water splitting at large current densities.

Developing low-cost and self-supported bifunctional catalysts for highly efficient water splitting devices is of great significance. Herein, different from previously reported NiFe2O4-based electrocatalysts, we have grown nano-NiFe2O4 directly onto the iron foil (IF) surface and in situ introduced Sn4+ into NiFe2O4. The resulting experimental phenomena confirmed that the as-synthesized Sn-NiFe2O4/IF can deliver large-current densities (>1000 mA cm-2) during oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) processes at a low overpotential. The needed overpotentials at the current density of 10 and 1000 mA cm-2 are 231 and 368 mV for OER and 57 and 439 mV for HER, respectively. Additionally, when applied for the two-electrode water splitting, the corresponding needed voltage for Sn-NiFe2O4/IF at the current density of 10 mA cm-2 was only 1.56 V, which was comparable to the commercial Pt/C-RuO2/IF electrode. Thus, the introduced Sn4+ greatly enhanced the electrocatalytic property of Sn-NiFe2O4/IF, resulting in a superior bifunctional catalyst that can be applied for large-scale hydrogen production.

A highly reversible force-assisted Li - CO2 battery based on piezoelectric effect of Bi0.5Na0.5TiO3 nanorods.

The use of light-assisted cathode is regarded as an effective approach to reduce the overpotential of lithium carbon dioxide (Li - CO2) batteries. However, the inefficient electron-hole separation and the complex discharge-charge reactions hamper the efficiency of CO2 photocatalytic reaction in battery. Herein, a highly reversible force-assisted Li - CO2 battery has been established for the first time by employing a Bi0.5Na0.5TiO3 nanorods piezoelectric cathode. The high-energy electron and holes generated by the piezoelectric cathode with ultrasonic force can effectively enhance the carbon dioxide reduction reaction (CDRR) and carbon dioxide evolution reaction (CDER) kinetics, thereby reducing the overpotentials during the discharge-charge processes. Moreover, the morphology of the discharge product (Li2CO3) can be modified via the dense surface electrons of the piezoelectric cathode, resulting in the promoted decomposition kinetics of Li2CO3 in charging progress. Thus, the force-assisted Li - CO2 battery with the unique piezoelectric cathode can adjust the output and input energy by ultrasonic wave, and provides an ultra-low charging platform of 3.52 V, and exhibits excellent cycle stability (a charging platform of 3.42 V after 100 h cycles). The investigation of the force-assisted process described herein provides significant insights to solve overpotential in the Li - CO2 batteries system.

Y-mediated optimization of 3DG-PbO2 anode for electrochemical degradation of PFOS.

In our previous study, the three-dimensional graphene-modified PbO2 (3DG-PbO2) anode was prepared for the effective degradation of perfluorooctanesulfonat (PFOS) by the electrochemical oxidation process. However, the mineralization efficiency of PFOS at the 3DG-PbO2 anode still needs to be further improved due to the recalcitrance of PFOS. Thus, in this study, the yttrium (Y) was doped into the 3DG-PbO2 film to further improve the electrochemical activity of the PbO2 anode. To optimize the doping amount of Y, three Y and 3DG codoped PbO2 anodes were fabricated with different Y3+ concentrations of 5, 15, and 30 mM in the electroplating solution, which were named Y/3DG-PbO2-5, Y/3DG-PbO2-15 and Y/3DG-PbO2-30, respectively. The results of morphological, structural, and electrochemical characterization revealed that doping Y into the 3DG-PbO2 anode further refined the ß-PbO2 crystals, increased the oxygen evolution overpotential and active sites, and reduced the electron transfer resistance, resulting in a superior electrocatalytic activity. Among all the prepared anodes, the Y/3DG-PbO2-15 anode exhibited the best activity for electrochemical oxidation of PFOS. After 120 min of electrolysis, the TOC removal efficiency was 80.89% with Y/3DG-PbO2-15 anode, greatly higher than 69.13% with 3DG-PbO2 anode. In addition, the effect of operating parameters on PFOS removal was analyzed by response surface, and the obtained optimum values of current density, initial PFOS concentration, pH, and Na2SO4 concentration were 50 mA/cm2, 12.21 mg/L, 5.39, and 0.01 M, respectively. Under the optimal conditions, the PFOS removal efficiency reached up to 97.16% after 40 min of electrolysis. The results of the present study confirmed that the Y/3DG-PbO2 was a promising anode for electrocatalytic oxidation of persistent organic pollutants.

Mussel-inspired self-healing hydrogel form pectin and cellulose for hemostasis and diabetic wound repairing.

Diabetic wound is considered as a kind of chronic wound prone to infection and difficult to repair due to high glucose level in the blood of patients. In this research, a biodegradable self-healing hydrogel with mussel inspired bioadhesion and anti-oxidation properties is fabricated based on Schiff-base cross-linking. The hydrogel was designed from dopamine coupled pectin hydrazide (Pec-DH) and oxidized carboxymethyl cellulose (DCMC) for mEGF loading as a diabetic wound repair dressing. The Pectin and CMC as natural feedstock endowed the hydrogel with biodegradability to avoid possible side effects, while the coupled catechol structure could enhance the tissue adhesion of the hydrogel for hemostasis. The results showed the Pec-DH/DCMC hydrogel formed fast and can cover irregular wounds with good sealing effect. The catechol structure also improved the reactive oxygen species (ROS) scavenging ability of the hydrogel, which can eliminate the negative effect of ROS during wound healing. The in vivo diabetic wound healing experiment revealed the hydrogel as mEGF loading vehicle greatly enhanced the diabetic wound repairing rate in mice model. As a result, the Pec-DH/DCMC hydrogel could show advantages as EGF carrier in wound healing applications.

Controllable preparation of Ti3C2Tx/Ag composite as SERS substrate for ultrasensitive detection of 4-nitrobenzenethiol.

Currently, metal carbonitride (MXene) has been identified as a hot research topic in the research area of surface-enhanced Raman scattering (SERS). In this study, Ti3C2Tx/Ag composite was fabricated as SERS substrate with different Ag contents. The fabricated Ti3C2Tx/Ag composites show good SERS behavior by detecting 4-Nitrobenzenethiol (4-NBT) probe molecules. Through calculation, the SERS enhancement factor (EF) of the Ti3C2Tx/Ag substrate was as high as 4.15 × 106. It is worth noting that the detection limit of 4-NBT probe molecules can be achieved ultralow concentration of 10-11 M. In this system, electromagnetic enhancement mechanism and chemical enhancement mechanism have synergistic effects on SERS phenomenon. Meanwhile, the Ti3C2Tx/Ag composite substrate exhibited good SERS reproducibility. In addition, the SERS detection signal hardly changed after 6 months of natural standing, and the substrate showed good stability. This work suggests that the Ti3C2Tx/Ag substrate could be used as a sensitivity SERS sensor for practical application, and could be applied in the field of environmental monitoring.

High-Performance Layered CaV4O9-MXene Composite Cathodes for Aqueous Zinc Ion Batteries.

Due to their reliability, affordability and high safety, rechargeable aqueous zinc ion batteries (ZIBs) have garnered a lot of attention. Nevertheless, undesirable long-term cycle performance and the inadequate energy density of cathode materials impede the development of ZIBs. Herein, we report a layered CaV4O9-MXene (Ti3C2Tx) composite assembled using CaV4O9 nanosheets on Ti3C2Tx and investigate its electrochemical performance as a new cathode for ZIBs, where CaV4O9 nanosheets attached on the surface of MXene and interlamination create a layered 2D structure, efficiently improving the electrical conductivity of CaV4O9 and avoiding the stacking of MXene nanosheets. The structure also enables fast ion and electron transport. Further discussion is conducted on the effects of adding MXene in various amounts on the morphology and electrochemical properties. The composite shows an improved reversible capacity of 274.3 mA h g-1 at 0.1 A g-1, superior rate capabilities at 7 A g-1, and a high specific capacity of 107.6 mA h g-1 can be delivered after 2000 cycles at a current density of 1 A g-1. The improvement of the electrochemical performance is due to its unique layered structure, high electrical conductivity, and pseudo capacitance behavior.

Graphene electrochemical transistors decorated by Ag nanoparticles exhibiting high sensitivity for the detection of paraquat over a wide concentration range.

Paraquat (PQ) is a nonselective contact herbicide used in agriculture for the control of broad leaf weeds, which would cause irreversible damage to human organs even at very low concentrations. Therefore, the trace residue detection of PQ in the environment is of vital importance. Here, a novel graphene electrochemical transistor (GECT) for PQ detection is reported for the first time. The key to the device design is the application of a layer of Ag nanoparticle (Ag NP) modified monolayer graphene as the channel layer. Due to the good electrochemical activity of Ag NPs for PQ detection, the device exhibits excellent sensitivity for PQ with the detection limit of 0.068 nM and a wide linear range from 0.1 nM to 5 mM. The GECT sensor also reveals good selectivity toward several common interferents and exhibits satisfactory recoveries for PQ detection when using Chinese cabbage as a simulant to deduce the real detection situation. The GECT sensor not only provides an efficient method for the detection of PQ residues, but also provides an effective grafting platform for the construction of novel high-sensitivity electrochemical sensors.

Cellulose based self-healing hydrogel through Boronic Ester connections for wound healing and antitumor applications.

The application of biodegradable hydrogels in medical field has drawn great attention because their networked structure provided ideal spaces for drug loading and cell growth. In this research, the boronic acid was coupled onto carboxyethyl cellulose (CMC) to synthesize boronic acid grafted CMC (CMC-BA) conveniently and self-healing hydrogel was fabricated with polyvinyl alcohol (PVA) crosslinking through dynamic boronic ester bond. The CMC-BA/PVA hydrogel showed good biocompatibility and could be degraded by cellulase and in vivo. The hydrogel formed fast fit for localized injection to cover the irregular wounds and localize the antitumor drugs to the tumor site. The in vivo wound repairing experiment revealed the hydrogel could form airtight adhesion to the wound site to reduce blood loss and accelerate the wound repairing rate. The hydrogel as a drug release carrier also reduced the acute in vivo toxicity of DOX with antitumor performance well preserved through a controlled release profile. Based on the above advantages, the CMC-based hydrogel with boronic ester connection should have great potential in biomedical areas with profitable future.

Development and validation of outcome prediction models for acute kidney injury patients undergoing continuous renal replacement therapy.

Object: This study aimed to develop and validate a set of practical predictive tools that reliably estimate the 28-day prognosis of acute kidney injury patients undergoing continuous renal replacement therapy. Methods: The clinical data of acute kidney injury patients undergoing continuous renal replacement therapy were extracted from the Medical Information Mart for Intensive Care IV database with structured query language and used as the development cohort. An all-subset regression was used for the model screening. Predictive models were constructed via a logistic regression, and external validation of the models was performed using independent external data. Results: Clinical prediction models were developed with clinical data from 1,148 patients and validated with data from 121 patients. The predictive model based on seven predictors (age, vasopressor use, red cell volume distribution width, lactate, white blood cell count, platelet count, and phosphate) exhibited good predictive performance, as indicated by a C-index of 0.812 in the development cohort, 0.811 in the internal validation cohort and 0.768 in the external validation cohort. Conclusions: The model reliably predicted the 28-day prognosis of acute kidney injury patients undergoing continuous renal replacement therapy. The predictive items are readily available, and the web-based prognostic calculator (https://libo220284.shinyapps.io/DynNomapp/) can be used as an adjunctive tool to support the management of patients.

V5+-Doped Potassium Ferrite as an Efficient Trifunctional Catalyst for Large-Current-Density Water Splitting and Long-Life Rechargeable Zn-Air Battery.

Developing non-noble metal catalyst with super trifunctional activities for efficient overall water splitting (OWS) and rechargeable Zn-air battery (ZAB) is urgently needed. However, catalysts with excellent oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and hydrogen evolution reaction (HER) performances are relatively few. Although metal-ionic-conductor K2Fe4O7 (KFO) can output large current densities for OER/HER even in 10.0 M KOH electrolyte, its water-splitting property still needs to be further improved. Herein, we introduced V5+ directly into KFO and synthesized the binder-free nickel foam (NF) basal V-KFO nanoparticles (labeled as V-KFO/NF). Both the theoretical analysis and actual experimental data certify that V5+ doping enhances the instinct water-splitting property of V-KFO/NF. Additionally, V-KFO/NF can directly serve as the air cathode of liquid/flexible ZABs. The assembled liquid ZAB can continue the charge-discharge cycling testing with a lower voltage gap (0.834 V) and a longer operation life (>550 h) at 10 mA cm-2. Meanwhile, the assembled flexible ZAB can drive the two-electrode water-splitting unit of V-KFO/NF and needs only 1.54 V to achieve the current density of 10 mA cm-2, which is much lower than that of KFO/NF (1.59 V). This work not only provides a novel and efficient trifunctional catalyst for a self-powered water-splitting device but also is the foundation support for other heteroatom-doped low-cost materials.

Self-healing pectin/cellulose hydrogel loaded with limonin as TMEM16A inhibitor for lung adenocarcinoma treatment.

Lung cancer as one of the highest incident malignant tumors did not receive satisfactory chemotherapy due to lack of specific drug targets and targeted drugs. This study screened a new effective lung tumor inhibitor limonin from herbal medicine, which inhibited proliferation and promoted apoptosis of lung adenocarcinoma cells by targeting specific high expressed TMEM16A ion channel. Moreover, a novel biodegradable self-healing hydrogel was prepared from acylhydrazide functionalized carboxymethyl cellulose (CMC-AH) and oxidized pectin (pec-CHO) to reduce the side effects of the limonin to the body. The hydrogels showed fast gelation, good biocompatibility and sustained limonin release property. The limonin-loaded hydrogel significantly inhibited the growth of lung adenocarcinoma in xenografts mice because the limonin inhibited the proliferation, migration and promoted apoptosis of LA795 cells, and eliminated the acute toxicity through sustained release from the hydrogel. Combined the antitumor performance of the limonin and sustained release of pec-CHO/CMC-AH hydrogel, this limonin/hydrogel system achieved satisfactory antitumor effect and eliminated side effects in vivo. Therefore, this system has great potential application for enhanced lung adenocarcinoma therapy.

Tailored FTO/Ag/ZIF-8 structure as SERS substrate for ultrasensitive detection.

In this work, a series of F-doped SnO2/Ag/zeolite imidazole framework (FTO/Ag/ZIF-8) sandwich structure have been successfully fabricated via a magnetic sputtering method and serve as surface-enhanced Raman scattering (SERS) substrate. The magnetic sputtering time of Ag was adjusted to obtain the optimal SERS substrate. The commonly used 4-mercaptobenzoic acid (4-MBA) molecules was selected for the SERS experiment. When the sputtering time of Ag nanoparticles (NPs) was 120 s, the FTO/Ag/ZIF-8 substrate showed the maximum SERS performance. In the system, the electromagnetic mechanism (EM) and charge-transfer (CT) enhancement mechanism have synergistic effect on the SERS phenomenon. Ag NPs was used to generate electromagnetic hot spots, which was beneficial to the EM mechanism. ZIF-8 could adsorb and capture more 4-MBA probe molecules to the hotspots. At the same time, CT happened between Ag, ZIF-8, and 4-MBA probe molecules, which was attribute to the CM mechanism. The enhancement factor (EF) of the composite SERS substrate was as high as 7.67 × 106. The detection limit of the substrate can reach 10-9 M of 4-MBA probe molecules. Moreover, the SERS templates showed good stability, the SERS signals almost unchanged after naturally kept for 6 months. Besides, due to the high sensitivity and good stability of the substrates, this work might broaden the potential practical application of SERS.

Cellulose-based thermo-responsive hydrogel with NIR photothermal enhanced DOX released property for anti-tumor chemotherapy.

Thermo-sensitive hydrogels change their properties through phase transition, which could be used to regulate various behaviors by changing the temperature. In this study, degradable hydrogels with thermo-response were designed by reaction of oxidized carboxymethyl cellulose (CMC-CHO) with functional P(NIPAM-co-AH). The hydrogels showed biocompatibility and thermo-response with lower critical solution temperature (LCST) regulated by weight ratio of P(NIPAM-co-AH)/CMC-CHO. The photo-thermal property of gold nanorod was triggered by the near-infrared (NIR) to enhance the DOX release for in vivo anti-tumor therapy of model mice. The results showed good biocompatibility and biodegradability of the hydrogel both in vitro and in vivo, and the DOX with hydrogel loading reduced the toxicity through sustained release behavior. The anti-tumor performance further enhanced with NIR triggered drug release regulated by photo-thermal property. In conclusion, the injectable P(NIPAM-co-AH)/CMC-CHO based self-healing hydrogels could act as promising drug delivery vehicle for potential localized anti-tumor therapy.

Highly Dispersed Antimony-Bismuth Alloy Encapsulated in Carbon Nanofibers for Ultrastable K-Ion Batteries.

Antimony-based alloys have appealed to an ever-increasing interest for potassium ion storage due to their high theoretical capacity and safe voltage. However, sluggish kinetics and the large radius of K+ lead to limited rate performance and severe capacity fading. In this Letter, highly dispersed antimony-bismuth alloy nanoparticles confined in carbon fibers are fabricated through an electrospinning technology followed by heat treatment. The BiSb nanoparticles are uniformly confined into the carbon fibers, which facilitate rapid electron transport and inhibit the volume change during cycling owing to the synergistic effect of the BiSb alloy and carbon confinement engineering. Furthermore, the effect of a potassium bis(fluorosulfonyl)imide (KFSI) electrolyte with different concentrations has been investigated. Theoretical calculation demonstrates that the incorporation of Bi metal is favorable for potassium adsorption. The combination of delicate nanofiber morphology and electrolyte chemistry endows the fiber composite with an improved reversible capacity of 274.4 mAh g-1, promising rate capability, and cycling stability upon 500 cycles.

Self-healing hydrogel based on polyphosphate-conjugated pectin with hemostatic property for wound healing applications.

Self-healing hydrogels have important application in hemostasis and wound repairing. In this research, pectin based self-healing hydrogel was fabricated with conjugated polyphosphate for hemostatic and wound healing applications. The hydrogel formed without any stimulus and hydrogel kept its biocompatibility; at the same time, the hydrogel degraded completely by enzyme and in vivo. The polyphosphate conjugated hydrogel also showed self-healing property and sustained release performance with strong coagulation characteristic. More importantly, the in vivo experiment revealed that the polyphosphate conjugated hydrogel reduced the blood loss and hemostasis time in hemorrhage model; meanwhile, the hydrogel accelerated the wound repairing rate of the open wound by preventing bacterial invasion. Altogether, the PolyP conjugated hemostatic pectin-based hydrogel is a good candidate as wound dressing material applied in clinic or open wound repairing.

Dealloying Synthesis of Silicon Nanotubes for High-Performance Lithium Ion Batteries.

The front cover artwork is provided by Dr. Ping Nie and Prof. Limin Chang at Jilin Normal University. The image shows one-dimensional silicon-nitrogen-doped carbon nanotube composite fabricated through a dealloying process. The nanotube engineered silicon coupled with conductive carbon coating synergistically boosts the electrochemical performance. Read the full text of the Research Article at 10.1002/cphc.202100832.

Oxygen Vacancy-Mediated Growth of Amorphous Discharge Products toward an Ultrawide Band Light-Assisted Li-O2 Batteries.

Photoassisted electrochemical reaction is regarded as an effective approach to reduce the overpotential of lithium-oxygen (Li-O2 ) batteries. However, the achievement of both broadband absorption and long term battery cycling stability are still a formidable challenge. Herein, an oxygen vacancy-mediated fast kinetics for a photoassisted Li-O2 system is developed with a silver/bismuth molybdate (Ag/Bi2 MoO6 ) hybrid cathode. The cathode can offer both double advantages for light absorption covering UV to visible region and excellent electrochemical activity for O2 . Upon discharging, the photoexcited electrons from Ag nanoplate based on the localized surface plasmon resonance (LSPR) are injected into the oxygen vacancy in Bi2 MoO6 . The fast oxygen reaction kinetics generate the amorphous Li2 O2 , and the discharge plateau is improved to 3.05 V. Upon charging, the photoexcited holes are capable to decompose amorphous Li2 O2 promptly, yielding a very low charge plateau of 3.25 V. A first cycle round-trip efficiency is 93.8% and retention of 70% over 500 h, which is the longest cycle life ever reported in photoassisted Li-O2 batteries. This work offers a general and reliable strategy for boosting the electrochemical kinetics by tailoring the crystalline of Li2 O2 with wide-band light.

Dealloying Synthesis of Silicon Nanotubes for High-Performance Lithium Ion Batteries.

Practical applications of silicon-based anodes in lithium ion batteries have attracted unprecedented attentions due to the merits of extraordinary energy density, high safety and low cost. Nevertheless, the inevitable huge volume change upon lithiation and delithiation brings about silicon electrode integrity damage and fast capacity fading, hampering the large-scale application. Herein, a novel one-dimensional tubular silicon-nitrogen doped carbon composite (Si@NC) with a core-shell structure has been fabricated using silicon magnesium alloy and polydopamine as a template and precursor. The as-obtained composite exhibits remarkable specific capacity and ultrafast redox kinetics, an outstanding cycling stability with fine capacity of 583.6 mAh g-1 at 0.5 A g-1 over 200 cycles is delivered. Moreover, a full cell matched with LiFePO4 cathode has demonstrated a reversible capacity of 148.8 mAh g-1 with high Coulombic efficiency as well as an excellent energy density of 396 Wh kg-1 . The nanotube structure engineering and silicon confined in nitrogen doped carbon effectively alleviate the volume expansion and endow the composite with superior stability. The robust strategy developed here gives a new insight into designing silicon anodes for enhanced lithium storage properties.

Image quality enhancement of transparent waveguide display using a twisted nematic mode polymer-stabilized liquid crystal.

In this study, a twisted nematic mode polymer-stabilized liquid crystal (TN mode PSLC) integrated with a crossed polarizer was used to create a transparent waveguide display. When a voltage was applied, the PSLC scattered the waveguide light with a high polarization selectivity such that no substantial loss of the outgoing light intensity was observed after integrating the polarizer. However, with a crossed polarizer, in the ON state, the background light was not only scattered but also absorbed by the analyzer. Using this device configuration, with a 12 µm cell gap and 7% monomer concentration, we successfully realized a normally transparent waveguide display. The contrast ratio of the waveguide outgoing light was 26 and that of the undesired background reached 90. This device can display images due to waveguide edge-lit light scattering and simultaneously block the background information to improve the image quality.

Light emitting CMC-CHO based self-healing hydrogel with injectability for in vivo wound repairing applications.

Self-healing hydrogels with biodegradability have great potential biomedical application in drug loading and delivery, wound dressing and tissue engineering. In this research, biodegradable hydrogels were designed from oxidized CMC (CMC-CHO) and PEO23 dinaphthoate hydrazide (PEO23 DNH) with naphthalene structure for potential bio-imaging purpose. Results showed that the gelation time of this self-healing hydrogels was very fit for in situ injectable applications for drug loading and controlled release. The hydrogels also showed excellent biocompatibility because all the components and the acylhydrazone bond are biocompatible. Moreover, the in vitro and in vivo drug release study revealed the CMC-CHO based hydrogels could reduce the acute toxicity of the drugs with a controlled and sustained release manner. The hydrogel also showed hemostatic activity by sealing effect and mEGF loaded hydrogel accelerated the wound repairing efficacy. All above result proved the CMC-CHO/PEO23 DNH hydrogel with luminescent property have great application property in bioscience and biotechnology.