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Background: Ferroptosis is an important iron‐dependent form of cell death in hepatocellular carcinoma (HCC). Sorafenib, a potent ferroptosis inducer, is used to treat advanced HCC but its efficacy is limited by the development of drug resistance. Methods: The effects of DUXAP8 expression on HCC progression were evaluated by TCGA database, Kaplan‐Meier analysis, and in situ hybridization analysis. Sorafenib resistant HCC cell lines were modeled in vitro to study the regulation of DUXAP8 on ferroptosis in HCC induced by sorafenib. We used RNA pull‐down, immunofluorescence assays, acyl‐biotinyl exchange assay and mass spectrometry analysis to assess the molecular mechanism of ferroptosis regulation by DUXAP8. Syngeneic subcutaneous and orthotopic CDX models were used to assess whether DUXAP8 inhibition improves HCC in vivo. Results: LncRNA DUXAP8, which is highly expressed in liver cancer and associated with poor prognosis, contributes to sorafenib resistance through suppression of ferroptosis. In vitro tests revealed that DUXAP8 reduced the sensitivity of HCC to sorafenib‐induced ferroptosis by acting on SLC7A11, a subunit of the amino acid antiporter system xc‐. DUXAP8 facilitates SLC7A11 palmitoylation and impedes its lysosomal degradation, thereby enhancing SLC7A11 action and suppressing ferroptosis. RNA pull‐down and immunofluorescence assays confirmed that DUXAP8 decreased membrane translocation and promoted sorting of de‐palmitoylated SLC7A11 to lysosomes by binding of DUXAP8 to SLC7A11. In addition, mass spectrometric analysis found that the Cys414 residue of SLC7A11 might be the predominant mutant site responsible for molecular masking of SLC7A11 lysosomal sorting. Further, the antitumor effect of DUXAP8 knockdown was verified in orthotopic and subcutaneous CDX models. Conclusions: Our findings suggest that a novel translational strategy combining sorafenib with DUXAP8 silencing to overcome drug resistance may improve treatment efficacy in patients with advanced HCC. [ABSTRACT FROM AUTHOR]

Background: The tumour microenvironment and cirrhotic liver are excellent sources of cancer-associated fibroblasts (CAFs), which participate in carcinogenesis. Thus, it is important to clarify the crosstalk between CAFs and HCC cells and the related mechanism in regulating carcinogenesis.Methods: Human hepatocellular carcinoma (HCC) tissues and matched adjacent normal tissues were obtained from HCC patients. Immunohistochemistry, Western blotting (WB) and RT-qPCR were performed to detect the expression of SCUBE1. The roles of SCUBE1 in inducing stemness features in HCC cells were explored and investigated in vitro and in vivo. Student's t tests or Mann-Whitney U tests were used to compare continuous variables, while chi-square tests or Fisher's exact tests were used to compare categorical variables between two groups.Results: SCUBE1 was confirmed to be highly expressed in CAFs in HCC and had a strong connection with stemness and a poor prognosis. In addition, CAFs were found to secrete SCUBE1 to enhance the malignancy of HCC cells and increase the proportion of CD133-positive cells. Silencing SCUBE1 expression had the opposite effect. The Shh pathway was activated by SCUBE1 stimulation. Inhibition of cyclopamine partially reversed the stimulating effect of SCUBE1 both in vivo and in vitro. Moreover, based on the RT-qPCR, ELISA and WB results, a high SCUBE1 expression level was found in HCC tissue and serum.Conclusion: This study revealed that CAFs-derived SCUBE1 can enhance the malignancy and stemness of HCC cells through the Shh pathway. This study aims to provide new perspectives for future HCC studies and provide new strategies for HCC treatment. [ABSTRACT FROM AUTHOR]

Here we report a new strategy to tune both excitation and emission peaks of upconversion nanoparticles (UCNPs) into the first infrared biowindow (NIR‐I, 650–900 nm) with high NIR‐I‐to‐NIR‐I upconversion efficiency. By introducing the sensitizer Nd3+, activator Er3+, energy migrator Yb3+ and energy manipulator Mn2+ into specific region to construct proposed energy migration processes in the designed core–shell–shell nanoarchitecture, back energy transfer (BET) from activator to sensitizer or migrator can be greatly blocked and the NIR‐to‐red upconversion emission can be efficiently promoted. Consequently, BET‐induced photon quenching and the undesired green‐emitting radiative transition are entirely eliminated, leading to high‐efficiency single‐band red upconversion emission upon 808 nm NIR‐I laser excitation. Our findings provide insights into fundamental lanthanide interactions and advance the development of UCNPs for bioapplications with techniques that overturn traditional limitations. [ABSTRACT FROM AUTHOR]

Here we report a new strategy to tune both excitation and emission peaks of upconversion nanoparticles (UCNPs) into the first infrared biowindow (NIR‐I, 650–900 nm) with high NIR‐I‐to‐NIR‐I upconversion efficiency. By introducing the sensitizer Nd3+, activator Er3+, energy migrator Yb3+ and energy manipulator Mn2+ into specific region to construct proposed energy migration processes in the designed core–shell–shell nanoarchitecture, back energy transfer (BET) from activator to sensitizer or migrator can be greatly blocked and the NIR‐to‐red upconversion emission can be efficiently promoted. Consequently, BET‐induced photon quenching and the undesired green‐emitting radiative transition are entirely eliminated, leading to high‐efficiency single‐band red upconversion emission upon 808 nm NIR‐I laser excitation. Our findings provide insights into fundamental lanthanide interactions and advance the development of UCNPs for bioapplications with techniques that overturn traditional limitations. [ABSTRACT FROM AUTHOR]

Cholangiocarcinoma (CCA) is a malignant hepatic tumor with a poor prognosis, which needs early diagnosis urgently. The gut microbiota has been shown to play a crucial role in the progression of liver cancer. Here, we explored a gut microbiota model covering genera Burkholderia-Caballeronia-Paraburkholderia , Faecalibacterium , and Ruminococcus_1 (B-F-R) for CCA early diagnosis. A case-control study was conducted to enroll 53 CCA patients, 47 cholelithiasis patients, and 40 healthy controls. The feces samples and clinical information of participants were collected in the same period. The gut microbiota and its diversity of individuals were accessed with 16S rDNA sequencing, and the gut microbiota profile was evaluated according to microbiota diversity. Finally, four enriched genera in the CCA group (genera Bacteroides , Muribaculaceae_unclassified , Muribaculum , and Alistipes) and eight enriched genera in the cholelithiasis group (genera Bifidobacterium , Streptococcus , Agathobacter , Ruminococcus_gnavus_group , Faecalibacterium , Subdoligranulum , Collinsella , Escherichia-Shigella) constitute an overall different microbial community composition (P = 0.001). The B-F-R genera model with better diagnostic value than carbohydrate antigen 19-9 (CA19-9) was identified by random forest and Statistical Analysis of Metagenomic Profiles (STAMP) to distinguish CCA patients from healthy controls [area under the curve (AUC) = 0.973, 95% CI = 0.932–1.0]. Moreover, the correlative analysis found that genera Burkholderia-Caballeronia-Paraburkholderia were positively correlated with body mass index (BMI). The significantly different microbiomes between cholelithiasis and CCA were found via principal coordinates analysis (PCoA) and linear discriminant analysis effect size (LEfSe), and Venn diagram and LEfSe were utilized to identify four genera by comparing microbial compositions among patients with malignant obstructive jaundice (MOJ-Y) or not (MOJ-N). In brief, our findings suggest that gut microbiota vary from benign and malignant hepatobiliary diseases to healthy people and provide evidence supporting gut microbiota to be a non-invasive biomarker for the early diagnosis of CCA. [ABSTRACT FROM AUTHOR]

Background: To explore the prognostic value of the fibrinogen–albumin ratio (FAR) combined with sarcopenia in intrahepatic cholangiocarcinoma (ICC) patients after surgery and to develop a nomogram for predicting the survival of ICC patients. Materials and Methods: In this prospective cohort study, 116 ICC patients who underwent radical surgery were enrolled as the discovery cohort and another independent cohort of 68 ICC patients was used as the validation cohort. Kaplan–Meier method was used to analyze prognosis. The independent predictor of overall survival (OS) and recurrence‐free survival (RFS) was evaluated by univariable and multivariable Cox regression analyses, then developing nomograms. The performance of nomograms was evaluated by concordance index (C‐index), calibration curve, receiver operating characteristic curve analysis (ROC), and decision curve analysis (DCA). Results: Patients with high FAR had lower OS and RFS. FAR and sarcopenia were effective predictors of OS and RFS. Patients with high FAR and sarcopenia had a poorer prognosis than other patients. OS nomogram was constructed based on age, FAR, and sarcopenia. RFS nomogram was constructed based on FAR and sarcopenia. C‐index for the nomograms of OS and RFS was 0.713 and 0.686. Calibration curves revealed great consistency between actual survival and nomogram prediction. The area under ROC curve (AUC) for the nomograms of OS and RFS was 0.796 and 0.791 in the discovery cohort, 0.823 and 0.726 in the validation cohort. The clinical value of nomograms was confirmed by the DCA. Conclusions: ICC patients with high FAR and sarcopenia had a poor prognosis, the nomograms developed based on these two factors were accurate and clinically useful in ICC patients who underwent radical resection. [ABSTRACT FROM AUTHOR]

CO2 photoreduction into valuable chemicals is a sustainable and prospective technology to alleviate greenhouse effects and the energy crisis. However, the photocatalytic efficiency is impeded by undesirable recombination of photogenerated carriers and poor CO2 activation performance. Herein, oxygen vacancies (OVs) are introduced into BiOBr atomic layers by ultraviolet light assisting to increase the efficiency of carrier separation and CO2 adsorption–activation performance, enhancing the CO2 reduction activity. The introduction of OVs can effectively enhance the visible light absorption, boost the photogenerated carrier separation migration, and tune the adsorption/desorption process for CO2 and products on the surface of photocatalysts. The optimized OVs engineering–mediated photocatalyst achieves a high CO generation rate of 10.15 μmol g−1 under visible light irradiation for 5 h in pure water, which is 1.99 times compared with that of pristine BiOBr atomic layers. The possible photocatalytic mechanism is investigated by in situ Fourier transform infrared spectroscopy (in situ FT‐IR) spectrometry. Also, an opportunity to design OVs‐rich ultrathin semiconductors for high‐performance CO2 reduction is offered. [ABSTRACT FROM AUTHOR]

Solar‐powered water evaporation provides a promising strategy for eco‐friendly and cost‐effective freshwater production. The exploration of high‐performance photothermal materials and the rational design of evaporation architectures are crucial in promoting solar steam generation efficiency. Herein, multidimensional MXene‐based composites with well‐organized heterojunction nanostructures are proposed as bifunctional photothermal materials. The solar thermal conversion, chemical stability, and photocatalysis degradation properties are enhanced by anchoring Co3O4 nanoparticles on delaminated ultrathin MXene nanosheets, compared with that of Ti3C2 MXene. Based on these advantages, an integrated 3D spherical evaporator is constructed using the Co3O4/Ti3C2 MXene‐based fabric. The evaporator shows its distinct advantages in maximizing the harvest of the hybrid energy from sunlight and the ambient environment, making it ideal for solar steam generation and synergetic water purification. An extremely high evaporation rate of 1.89 kg m−2 h−1 with a corresponding light‐to‐vapor energy conversion efficiency beyond the theoretical limit (130.4%) is achieved. More importantly, while the evaporation rate of the 2D evaporator significantly recedes upon the oblique sunlight irradiation, the evaporation rate of the 3D spherical evaporator is constantly high at different incident angles of sunlight, which satisfies the requirement of practical applications under moving sun. [ABSTRACT FROM AUTHOR]

Ultrasmall and homogeneous bimetallic PdxBi nanoalloys are well distributed on a Vulcan carbon support by a facile, low-cost synthetic strategy. The electrochemical activity of the as-prepared homogeneous PdxBi nanoalloy/carbon black nanocomposites is closely related to the content of Bi, revealing their excellent electrocatalytic performance for selective oxidation of monohydric alcohols and vicinal diols in alkali medium. [ABSTRACT FROM AUTHOR]

2 D transition metal dichalcogenide materials with layered nanostructures and specific phases usually exhibit excellent catalytic activities for the hydrogen evolution reaction (HER). A facile solvothermal process was used to prepare ultrathin noble‐metal‐free 2 D biphasic MoSe2 nanosheets composed of a metastable metallic 1T phase and a semiconducting 2H phase. High metallic 1T phase content and few‐layer‐thick MoSe2 nanosheets were obtained by tuning the amount of NaBH4 used in the reaction. The optimal integration of a metallic 1T phase and an environmentally stable 2H phase in MoSe2 electrocatalysts provides abundant active sites and good conductivity beneficial for the HER. The combination of experimental results and DFT calculations implies that the electrocatalytic activity for the HER on the MoSe2 surface goes through a collaborative Heyrovsky and Volmer reaction process. The theoretical studies suggest that the presence of 1T‐MoSe2 could reduce the band energy relative to 2H‐MoSe2 and, consequently, accelerate the sluggish HER kinetics of 2H‐MoSe2. This work provides valuable and novel insights into the understanding of the structure–activity relationships in 2 D transition metal dichalcogenide electrocatalysts. [ABSTRACT FROM AUTHOR]

A highly sensitive triple-amplification assay for the detection of microRNA (miRNA) let-7a is reported in this work. The assay relies on the formation of magnetic two-dimensional DNA/Fe3O4 nanosheet networks initiated by the target miRNA-associated hybridization chain reaction. The Fe3O4 nanosheets in the DNA/Fe3O4 networks display peroxidase-like catalytic activity towards a colorimetric reaction, thereby producing a highly sensitive signal for the quantification of let-7a. Under optimal conditions, the assay achieved a detection limit of 13 aM at a signal-to-noise ratio of 3 and a linear calibration plot between 0.05 fM and 12 nM. Successful attempts were made in the quantification of let-7a in serum samples. [ABSTRACT FROM AUTHOR]

A novel Ag3PO4/AgBr composite with Z-Scheme structure was constructed and synthesized via a simple in situ ion-exchange strategy on the surface of Ag3PO4 tetrahedra in an alkaline environment. The as-prepared Ag3PO4/AgBr composite has an intimate contact interface and exhibited enhanced visible-light photocatalytic activity, accompanied by superior stability toward degradation of methylene blue (MB) in aqueous solution. Also, a variety of pollutants can be degraded without selectivity, and the degradation efficiency was over 96%. Changes in the bandgap and the detailed degradation mechanism of the Ag3PO4/AgBr composite were analyzed and revealed using characterization analysis, theoretical calculations, and further designed experiments. Sufficient interfacial contact between Ag3PO4 and AgBr was favorable for transferring carriers and lengthening the lifetime of the Z-Scheme system, which simultaneously inhibit photocorrosion and maintain a high degradation rate. The trapping experiments indicate that h+ is a dominant reactive species for the degradation of MB. This Ag3PO4/AgBr photocatalyst with Z-Scheme structure shows great potential for replication and large scale impact on the environmental purification of organic pollutants. [ABSTRACT FROM AUTHOR]

Abstract: Nickel‐based materials are a type of cost‐effective catalyst for urea oxidation. Herein, we first reported nanostructured Ni2P−C as an efficient catalyst for urea electrooxidation. The Ni2P−C catalyst was prepared by a facile hydrothermal method and the structure and morphology were further characterized by X‐ray diffraction (XRD) and transmission electron microscope (TEM). The hexagonal crystal structure for Ni2P was indicated by the characteristic peaks in the XRD patterns, and lattice fringes of Ni2P were clearly observed in the high‐resolution TEM images. The catalytic ability for urea electrooxidation was studied by cyclic voltammetry and chronoamperometry techniques. It was found that the current density at 0.5 V was ca. 70.4 mA cm−2, about 2.7 times higher than that of the referenced commercial nickel oxide catalyst. A good catalytic stability for urea oxidation was also obtained. A diffusion‐controlled process was observed for urea oxidation on Ni2P catalyst while the active sites arising from Ni(II) ion oxidation was following a surface‐redox‐reaction‐controlled process. Kinetics studies by impedance spectroscopy and Tafel slope analysis displayed improved charge‐transfer kinetics towards urea electrooxidation. The results demonstrated that Ni2P would have potential applications for catalytic urea oxidation. [ABSTRACT FROM AUTHOR]

Activated graphene (AG) with various specific surface areas, pore volumes, and average pore sizes is fabricated and applied as a matrix for sulfur. The impacts of the AG pore structure parameters and sulfur loadings on the electrochemical performance of lithium-sulfur batteries are systematically investigated. The results show that specific capacity, cycling performance, and Coulombic efficiency of the batteries are closely linked to the pore structure and sulfur loading. An AG3/S composite electrode with a high sulfur loading of 72 wt.% exhibited an excellent long-term cycling stability (50% capacity retention over 1,000 cycles) and extra-low capacity fade rate (0.05% per cycle). In addition, when LiNO was used as an electrolyte additive, the AG3/S electrode exhibited a similar capacity retention and high Coulombic efficiency (∼98%) over 1,000 cycles. The excellent electrochemical performance of the series of AG3/S electrodes is attributed to the mixed micro/mesoporous structure, high surface area, and good electrical conductivity of the AG matrices and the well-distributed sulfur within the micro/mesopores, which is beneficial for electrical and ionic transfer during cycling. [ABSTRACT FROM AUTHOR]

Asymmetric supercapacitors (ASCs) have attracted growing interest and attention in the field of supercapacitors owing to their high energy density and power density. In this work, ordered mesoporous Co3O4 samples with different pore sizes (ca. 20 nm and ca. 70 nm) are prepared via a hard template method. Flexible solid-state ASC devices based on mesoporous Co3O4 with pore size of 20 nm and activated carbon possesses a specific capacitance of 215 mF cm−2 (at 1.5 mA cm−2) and show excellent cycling performance. Electrochemical tests reveal that the mesoporous material with a larger specific surface area, that is, a smaller primary particle size, is more suitable for solid-state ASC device. The results provide a potential electrode material for ACSs. [ABSTRACT FROM AUTHOR]

Ordered porous CoO materials with pore sizes of 5 nm (CoO-5), 20 nm (CoO-20), and 70 nm (CoO-70) have been synthesized via a hard-template method and were studied as catalysts to bring insight into non-enzymatic electrochemical sensing of glucose. A glassy carbon electrode modified with CoO-70 responds more quickly and sensitively to glucose than those modified with CoO-5 or CoO-20. The sensor based on the use of CoO-70 and operated at a working voltage of 0.6 V (vs. Ag/AgCl) in 0.1 M NaOH solution shows a lower detection limit of 0.025 μM, good repeatability and high selectivity over ascorbic acid, uric acid, dopamine, and KCl. These results suggest that ordered porous CoO is a promising material for quantitative electrochemical determination of glucose, and that the pore size has a strong effect on performance. [ABSTRACT FROM AUTHOR]

Dextromethorphan is recognized as a substance of abuse around the world. An estimated 3.1 million people between the ages of 12 and 25 years (5.3%) misused over-the-counter cough and cold medications in 2006. In this study, we developed a serum metabolomic method by gas chromatography-mass spectrometry (GC-MS) to evaluate the effect of abuse of dextromethorphan on rats. The dextromethorphan-treated rats were given 12, 24 and 48 mg/kg (low, medium, high) of dextromethorphan by intragastric administration each day for 3 days. Partial least squares-discriminate analysis revealed that intragastric administration of dextromethorphan induced metabolic perturbations. Compared with the control (healthy) group, the levels of propanoic acid, urea, heptafluorobutanoic acid, 2-hexyldecanoic acid and butanedioic acid of the low group decreased; levels of propanoic acid and heptafluorobutanoic acid of the medium group decreased, while that of benzoic acid increased; and levels of 2-hexyldecanoic acid, glycerol and butanedioic acid of the high group increased. These biomarkers are involved in the citric acid cycle, urea cycle, glycerolipid metabolism and tricarboxylic acid cycle. The results indicate that the metabolomic method by GC-MS may be useful to elucidate abuse of dextromethorphan. According to the pathological changes in the liver at different dosages, dextromethorphan is not hepatotoxic after intragastric administration of 12, 24 and 48 mg/kg for 3 days. [ABSTRACT FROM AUTHOR]

β-SiC is a suitable photocatalyst for hydrogen evolution reaction because of its proper band structure (2.36 eV) and high chemical stability. Porousβ-SiC has a large surface area that can increase the number of reactive sites and shorten the charge transport pathways between the material interior and surface, thereby significantly improving the hydrogen evolution reaction performance. In the present study, hierarchical macroporousβ-SiC monolith composed of nanocrystals was directly prepared using SiO2opal as both template and precursor via the magnesiothermic reduction method at 750 °C. An interfacial magnesiothermic reaction model was presented as well. Theβ-SiC sample exhibited high photoelectric conversion performance and stability as a catalyst for hydrogen evolution. [ABSTRACT FROM AUTHOR]

Seeking high-capacity, high-rate, and durable anode materials for lithium-ion batteries (LIBs) has been a crucial aspect to promote the use of electric vehicles and other portable electronics. Here, a novel alloy-forming approach to convert amorphous Si (a-Si)-coated copper oxide (CuO) core-shell nanowires (NWs) into hollow and highly interconnected Si-Cu alloy (mixture) nanotubes is reported. Upon a simple H2 annealing, the CuO cores are reduced and diffused out to alloy with the a-Si shell, producing highly interconnected hollow Si-Cu alloy nanotubes, which can serve as high-capacity and self-conductive anode structures with robust mechanical support. A high specific capacity of 1010 mAh g−1 (or 780 mAh g−1) has been achieved after 1000 cycles at 3.4 A g−1 (or 20 A g−1), with a capacity retention rate of ≈84% (≈88%), without the use of any binder or conductive agent. Remarkably, they can survive an extremely fast charging rate at 70 A g−1 for 35 runs (corresponding to one full cycle in 30 s) and recover 88% capacity. This novel alloy-nanotube structure could represent an ideal candidate to fulfill the true potential of Si-loaded LIB applications. [ABSTRACT FROM AUTHOR]

Mesoporous NiO nanosheets with a single-crystalline structure were investigated as an oxygen electrode catalyst in a non-aqueous Li–O2 battery. The recharge voltage plateau achieved for the NiO-based Li–O2 battery was ca. 3.95 V, ca. 200 mV negatively shifted compared with that for β-Ni(OH)2 and acetylene black. The reaction mechanism during the charge process for the NiO-based Li–O2 battery was intensively researched. The results of X-ray photoelectron spectroscopy characterization indicated that Li2O2 and Li2CO3 were formed during the discharge process, which can be decomposed after recharge. These demonstrated that the NiO nanosheet exhibited a good activity for the decomposition of Li2O2 and Li2CO3. Furthermore, the results of the gas chromatography-mass spectrometry test reflected two steps of the recharge process, i.e., the oxidation of Li2O2 when the potential was below 4.0 V and the decomposition of Li2O2 and Li2CO3 when the potential was above 4.0 V. Moreover, no obvious performance decay was observed in the NiO-based battery even after 40 cycles when the capacity was limited to 500 mA h g−1, indicating an impressive cycling performance. [ABSTRACT FROM AUTHOR]

A three-dimensional (3D) carbonaceous aerogel derived from sustainable bacterial cellulose (BC) is introduced as a flexible framework for sulfur in lithium–sulfur batteries. The 3D carbonized BC (CBC) with highly interconnected nanofibrous structure exhibits good electrical conductivity and mechanical stability. The intrinsic macroporous structure of CBC contributes to a high sulfur loading of 81 wt%. Microstructure and morphology characterization results demonstrate that the sulfur species wrapped around CBC nanofibers are well dispersed. Even at such a high loading, the S/CBC composite still contains sufficient free space to accommodate the volume expansion of sulfur during lithiation. Furthermore, with an ultralight CBC interlayer inserted between the sulfur cathode and separator, significant improvement is achieved in active material utilization, cycling stability, and coulombic efficiency. The CBC interlayer can provide an extra conductive framework and adsorb migrating polysulfides to a certain degree. The CBC interlayer can also act as an additional collector for sulfur and thus could prevent the over-aggregation of insulated sulfur on the cathode surface. The good electrochemical performance reported in this work can be ascribed to the flexible 3D-interconnected nanostructure of the carbon framework and the rational design of battery configuration. [ABSTRACT FROM AUTHOR]

Mesoporous silicon microspheres were fabricated via in situ magnesiothermic reduction of silicon oxide. Scanning and transmission electron microscopy images indicate that the diameter of the mesoporous silicon microspheres is approximately 500 nm. Mesopores with diameters ranging from 10 to 30 nm are homogeneously distributed in the silicon microspheres. The as-prepared mesoporous silicon microspheres show a reversible capacity of 3000 mAh g at 100 mA g discharge current density. After 60 cycles, the mesoporous silicon microspheres can still deliver a 1500 mAh g capacity at 1000 mA g discharge current density. The high reversible capacity, excellent cycling, and good rate capability of the fabricated material can be attributed to its mesoporous morphology and ultrafine particle size. [ABSTRACT FROM AUTHOR]

For building high-energy density asymmetric supercapacitors, developing anode materials with large specific capacitance remains a great challenge. Although Fe2O3 has been considered as a promising anode material for asymmetric supercapacitors, the specific capacitance of the Fe2O3-based anodes is still low and cannot match that of cathodes in the full cells. In this work, a composite material with well dispersed Fe2O3 quantum dots (QDs, ≈2 nm) decorated on functionalized graphene-sheets (FGS) is prepared by a facile and scalable method. The Fe2O3 QDs/FGS composites exhibit a large specific capacitance up to 347 F g−1 in 1 m Na2SO4 between -1 and 0 V versus Ag/AgCl. An asymmetric supercapacitor operating at 2 V is fabricated using Fe2O3/FGS as anode and MnO2/FGS as cathode in 1 m Na2SO4 aqueous electrolyte. The Fe2O3/FGS//MnO2/FGS asymmetric supercapacitor shows a high energy density of 50.7 Wh kg−1 at a power density of 100 W kg−1 as well as excellent cycling stability and power capability. The facile synthesis method and superior supercapacitive performance of the Fe2O3 QDs/FGS composites make them promising as anode materials for high-performance asymmetric supercapacitors. [ABSTRACT FROM AUTHOR]

Porous activated carbon with a ultrahigh specific surface area (3164 m2 g-1) and large pore volume (1.88 cm3 g-1) was prepared from waste litchi shells with channel-like macropores via a KOH activation method. The macroporous structure of litchi shells is believed to be conducive to distribute the activation agent, which enables sufficient activation. The as-prepared activated carbon was developed as a conducting framework for lithium-sulfur battery cathode materials. The resulting activated carbon/sulfur composite cathode possesses a high specific capacity, good rate capability, and long-term cycling performance. At 200 mA g-1 current density, the initial discharge capacity of the activated carbon/sulfur composite cathode with 60 wt% sulfur content is 1105 mA h g-1 At a current density of 800 mA g-1, the activated carbon/sulfur composite cathode shows 51% capacity retention over 800 cycles with a fade rate of 0.06% per cycle. The coulombic efficiency of the cell remains at approximately 95%. By adding LiNO3 in the electrolyte, the activated carbon/sulfur composite electrode tested at 800 mA g-1 shows a high coulombic efficiency (>99%). The activated carbon/sulfur composites exhibited similar capacity value and cycling trends with an increase in sulfur content from 60% to 68%. The good electrochemical performance can be attributed to the excellent structural parameters of the activated carbon. The ultrahigh specific surface area and large pore volume not only enhances the sulfur content but also ensures dispersion of elemental sulfur in the conducting framework, thereby improving sulfur utilization. The small nanopores of the activated carbon can effectively inhibit the diffusion of polysulfides during the charge/discharge process. [ABSTRACT FROM AUTHOR]

Monodisperse mesoporous anatase microspheres were prepared by a combination of sol-gel and liquid-crystal template methods. With the change in annealing temperature, the pore structure parameters of samples were regulated. The influence of pore structure parameters on lithium-ion battery performance was systematically investigated. Results of electrochemical test and analysis demonstrated that the pore structure parameters significantly influenced the specific capacity, charging and discharging curves, rate capability, and cycle performance of the batteries. The first irreversible capacity increased with increased specific surface area. Materials with larger specific surface area showed better rate capability. When the average pore size was too small, the transport of Li in the electrolyte was impeded, which affected the rate capability of the materials. Based on the charging and discharging curves, the capacity of the plateau section corresponding to lithium insertion/extraction ions in the interstitial octahedral sites of anatase became smaller with increased specific surface area. By contrast, the capacity of the oblique line section corresponding to the Li insertion/extraction into/from the surface layer of anatase became larger. The pore volume influenced the cycling stability. [ABSTRACT FROM AUTHOR]

Network structured carbonized bacterial cellulose-supported Ru nanoparticles (CBC/Ru), which provide sufficient space for Li2O2 deposition without a significant volume effect and improve the transport of oxygen and electrons, were used as the binder-free oxygen electrode in a Li–O2 battery. The CBC/Ru exhibited high activities and good stability during discharge–recharge processes. [ABSTRACT FROM AUTHOR]

Transition metal sulfides are cheap and efficient catalysts for water splitting to produce hydrogen; these compounds have attracted wide attention. Nickel sulfide (NiS2) has been studied in depth because of its simple preparation process, excellent performance and good stability. Here, we propose a modification to the hydrothermal synthesis method for the fabrication of a highly efficient and stable NiS2 electrocatalyst prepared by two different sulfur sources, i.e., sulfur powder and C3H7NaO3S2 (MPS), for application in hydrogen evolution reactions. The obtained NiS2 demonstrated excellent HER performance with an overpotential of 131 mV to drive -10 mA cm−1 in 0.5 M H2SO4 solution with 5mV performance change after 1000 cycles of stability testing. We believe that this discovery will promote the industrial development of nonprecious metal catalysts. [ABSTRACT FROM AUTHOR]

Biosensors are widely used in production and life, and can be used in medicine, industrial production, and scientific research. Among them, the detection of pH has always received extensive attention. In this study, we demonstrate the use of a one-step hydrothermal method to prepare Co-FeS2/CoS2 nanomaterials as pH sensor (pH vs. overpotential) for the first time. The proposed pH sensor exhibits outstanding performance in KOH solutions via electrochemical methods with good stability. Overall, the results of this study not only add to the non-noble transition metal electrocatalysis research, but also identify important sensing characteristics for electrocatalysts. [ABSTRACT FROM AUTHOR]

Ammonia (NH3) is a harmful gas contaminant that is part of the nitrogen cycle in our daily lives. Therefore, highly sensitive ammonia sensors are important for environmental protection and human health. However, it is difficult to detect low concentrations of ammonia (≤50 ppm) using conventional means at room temperature. Tin monoxide (SnO), a member of IV–VI metal monoxides, has attracted much attention due to its low cost, environmental-friendly nature, and higher stability compared with other non-oxide ammonia sensing material like alkaline metal or polymer, which made this material an ideal alternative for ammonia sensor applications. In this work, we fabricated high-sensitive ammonia sensors based on self-assembly SnO nanoshells via a solution method and annealing under 300 °C for 1 h. The as fabricated sensors exhibited the response of 313%, 874%, 2757%, 3116%, and 3757% (∆G/G) under ammonia concentration of 5 ppm, 20 ppm, 50 ppm, 100 ppm, and 200 ppm, respectively. The structure of the nanoshells, which have curved shells that provide shelters for the core and also possess a large surface area, is able to absorb more ammonia molecules, leading to further improvements in the sensitivity. Further, the SnO nanoshells have higher oxygen vacancy densities compared with other metal oxide ammonia sensing materials, enabling it to have higher performance. Additionally, the selectivity of ammonia sensors is also outstanding. We hope this work will provide a reference for the study of similar structures and applications of IV–VI metal monoxides in the gas sensor field. [ABSTRACT FROM AUTHOR]