1D/3D dual carbon-supported Mott-Schottky-type Co-Co2P heterojunctions for pH-universal hydrogen evolution.

The rational design of low-cost, efficient, and stable heterojunction catalysts for pH-universal hydrogen evolution is attracting increasing attention towards a sustainable hydrogen economy. Herein, a sequential spatial restriction-pyrolysis route is developed to confine Mott-Schottky-type Co-Co2P heterojunctions embedded in the one-dimensional (1D) carbon nanotube-modified three-dimensional (3D) N,P dual-doped carbon matrix (Co-Co2P@CNT//CM). The synergistic effect between the abundant Mott-Schottky heterointerfaces and the 1D/3D dual carbon confinement system enables fully exposed active sites and facilitated charge transfer dynamics, thus triggering favorable electronic structures of Co-Co2P@CNT//CM. As a result, Co-Co2P@CNT//CM heterojunctions exhibit excellent pH-universal hydrogen evolution reaction (HER) performance with overpotentials of 142, 205, and 262 mV at 10 mA cm-2 in 0.5 M H2SO4, 1.0 M KOH, and 1.0 M phosphate buffer saline (PBS), respectively. The theoretical results demonstrated that the Mott-Schottky effect can induce an oriented interfacial charge exchange between Co and Co2P. This can lower the reactive kinetic barrier and endow Co-Co2P@CNT//CM with ideal hydrogen adsorption free energy, which efficiently drives the production of H2 from electrolytic water.

Pulmonary reversed halo cycles and consolidations after immunotherapy: A case report.

BACKGROUND: Immune checkpoint inhibitor-associated interstitial lung disease (ICI-ILD) and opportunistic pneumonias are the main pulmonary complications during immunotherapy for malignancies. The organizing pneumonia (OP) pattern is one of the common radiological manifestations of ICI-ILD, and OP is the most common cause of reversed halo cycles and consolidations. However, opportunistic pneumonias should be excluded. CASE SUMMARY: In this report, we described a case of a 44-year-old man with esophageal cancer who showed multiple reversed-halo cycles and consolidations on chest computed tomography (CT) after he had a cold during immunotherapy. He was diagnosed with esophageal squamous-cell cancer (T2NIM0) after surgery. Then, he was successfully treated with 6 cycles of chemotherapy plus tislelizumab, one cycle of radiotherapy and 9 cycles of tislelizumab. Two months later, he complained of low-grade fever and cough with nonpurulent sputum after he had a cold. Community-acquired pneumonia was considered, but moxifloxacin was ineffective. Chest CT showed multiple reversed-halo cycles and consolidations. Mycobacterium tuberculosis was identified with next-generation sequence analysis of bronchoalveolar lavage fluid (BALF). Two months later, he improved with standard anti-tuberculosis medications. Both the cycles and consolidations disappeared in the repeat CT after 6 mo of medications. CONCLUSION: When chest CT shows reversed-halo cycles and consolidations in patients during anticancer immunotherapy, both ICI-ILD and infectious pneumonia should be considered. BALF microbiological analysis was helpful to differentiate them.

Engineering Double Sulfur-Vacancy in CoS1.097@MoS2 Core-Shell Heterojunctions for Hydrogen Evolution in a Wide pH Range.

Heterostructured nanomaterials have arisen as electrocatalysts with great potential for hydrogen evolution reaction (HER), considering their superiority in integrating different active components but are plagued by their insufficient active site density in a wide pH range. In this report, double sulfur-vacancy-decorated CoS1.097@MoS2 core-shell heterojunctions are designed, which contain a primary structure of hollow CoS1.097 nanocubes and a secondary structure of ultrathin MoS2 nanosheets. Taking advantage of the core-shell type heterointerfaces and double sulfur-vacancy, the CoS1.097@MoS2 catalyst exhibits pH-universal HER performance, achieving the overpotentials at 10 mA cm-2 of 190, 139, and 220 mV in 0.5 M H2SO4, 1.0 M KOH, and 1.0 M PBS, respectively. Systematic theoretical results show that the double sulfur-vacancy can endow the CoS1.097@MoS2 core-shell heterojunctions with promoted electron/mass transfer and enhanced reactive kinetics, thus boosting HER performance. This work clearly demonstrates an indispensable role of double sulfur-vacancy in enhancing the electrocatalytic HER performance of core-shell type heterojunctions under a wide pH operating condition.

Neuroimaging anomalies in asymptomatic middle cerebral artery steno-occlusive disease with normal-appearing white matter.

Background: Asymptomatic chronic cerebrovascular steno-occlusive disease is common, but the cognitive function and alterations in the brain's structural and functional profiles have not been well studied. This study aimed to reveal whether and how patients with asymptomatic middle cerebral artery (MCA) steno-occlusive disease and normal-appearing white matter differ in brain structural and functional profiles from normal controls and their correlations with cognitive function. Methods: In all, 26 patients with asymptomatic MCA steno-occlusive disease and 22 healthy controls were compared for neurobehavioral assessments, brain volume, cortical thickness, fiber connectivity density (FiCD) value, and resting-state functional connectivity (FC) using multimodal MRI. We also investigated the associations between abnormal cortical thicknesses, FiCD values, and functional connectivities with the neurobehavioral assessments. Results: Patients performed worse on memory tasks (Auditory Verbal Learning Test-Huashan version) compared with healthy controls. Patients were divided into two groups: the right group (patients with right MCA steno-occlusive disease) and the left group (patients with left MCA steno-occlusive disease). The left group showed significant cortical thinning in the left superior parietal lobule, while the right group showed significant cortical thinning in the right superior parietal lobule and caudal portion of the right middle frontal gyrus. Increased FiCD values in the superior frontal region of the left hemisphere were observed in the left group. In addition, a set of interhemispheric and intrahemispheric FC showed a significant decrease or increase in both the left and right groups. Many functional connectivity profiles were positively correlated with cognitive scores. No correlation was found between cortical thickness, FiCD values, and cognitive scores. Conclusion: Even if the patients with MCA steno-occlusive disease were asymptomatic and had normal-appearing white matter, their cognitive function and structural and functional profiles had changed, especially the FC. Alterations in FC may be an important mechanism underlying the neurodegenerative process in patients with asymptomatic MCA steno-occlusive disease before structural changes occur, so FC assessment may promote the detection of network alterations, which may be used as a biomarker of disease progression and therapeutic efficacy evaluation in these patients.

Ultrathin coordination polymer nanosheets modified with carbon quantum dots for ultrasensitive ammonia sensors.

Exposure to ammonia (NH3) is known harmful to health, environment and industrial facilities, hence it is important for the trace detection of NH3. Herein, for the first time, ultrasensitive room temperature NH3 sensors are realized by assembling carbon quantum dots (CQDs) on free-standing ultrathin coordination polymers (CPs) nanosheets (Co[Ni(CN)4]) with an average thickness of ∼2.5 nm, which demonstrate excellent sensitivity (Ra/Rg = 87.7 to 30 ppm), fast gas response speed (∼10 s to 30 ppm), remarkable repeatability, high selectivity, good long-term stability and low limit of theoretical detection (∼8 ppb) toward NH3 gas. The NH3 gas sensor enhancement through incorporation of CQDs provides a simple and environment-friendly strategy for further improving sensor property of CPs nanosheets. This work provides an effective way to construct new electrode materials for high-performance gas sensor devices via the rational design.

The pattern of brain metabolism in chronic steno-occlusive cerebral artery disease.

Background: Dispersion of gray matter and white matter and abnormal hemodynamic changes are common in patients with chronic stenosis cerebral artery disease. It is not easy to capture these abnormal changes with conventional magnetic resonance imaging (MRI). Magnetic resonance spectroscopy (MRS) is useful for obtaining metabolic information in either preclinical or clinical applications. The aim of our study was to apply MRS to non-invasively investigate changes in brain metabolism in MRI-negative patients with chronic cerebral artery steno-occlusive disease. Methods: We performed MRS examinations with 3.0T MRI on 34 patients with severe unilateral middle cerebral artery (MCA) stenosis or occlusion without parenchymal abnormalities. Additionally, N-acetylaspartic acid (NAA), creatine (Cr), choline (Cho), NAA/Cr, and Cho/Cr in the coronal, parenchymal, and thalamic regions of the affected brain and contralateral brain were determined. The mean concentrations of NAA, Cr, Cho, NAA/Cr, and Cho/Cr in the coronal, parenchymal, and thalamic regions of the ipsilateral and contralateral brains were compared using the 2-tailed paired t-test. Results: At the ipsilateral corona radiata and lenticular nucleus, the mean NAA was significantly lower, whereas the Cho and Cho/Cr were significantly higher than the contralateral corona radiata and lentiform nucleus (P<0.05). In addition, the creatine and NAA/Cr values in the coronal region of the affected side were significantly lower than those in the opposite side (P<0.05), but there was no significant difference between the pectin nuclei on both sides. No metabolic changes were found at the ipsilateral thalamus. Conclusions: In this study, we demonstrated that MRS could reveal metabolic changes and that the NAA, NAA/Cr, Cho, and Cho/Cr concentration might be used as indexes for evaluating neuronal damage in the chronic steno-occlusive cerebral artery disease, treatment strategies, and treatment effectiveness.

A cross-sectional survey on the rate of awareness of hepatitis B virus (HBV) infection and the prevention of mother-to-child transmission among hepatitis B surface antigen (HBsAg)-positive pregnant women.

Background: Mother-to-child transmission (MTCT) remains the main transmission route of hepatitis B virus (HBV) in China. Hepatitis B surface antigen (HBsAg) positive pregnant women were the main participants in MTCT of HBV. Nevertheless, little was known about their knowledge and awareness of HBV infection and MTCT. We intended to evaluate their knowledge of HBV infection and MTCT prevention, and to clarify the emphasis of health education to improve the control of MTCT of HBV. Methods: We invited 164 HBsAg-positive pregnant women, who were aged ≥18 years old, had basic literacy skills and visited the Outpatient Clinic of Infectious Disease of the Sun Yat-Sen Memorial Hospital from May 2019 to January 2020, to independently and anonymously complete a self-administered survey regarding their knowledge of HBV infection and MTCT prevention. The correct rate of the questions was calculated and analyzed. A multivariate regression was conducted to identify predictors of HBV and MTCT knowledge and awareness. Results: The average awareness rate of the 164 respondents was 52.56%, among which the awareness rates of basic knowledge and the transmission route of HBV were 80.49% and 53.29%, respectively. The awareness rates of knowledge about the interruption measures of MTCT during pregnancy, delivery, and postpartum were 43.78%, 49.75%, and 31.25%, respectively. The respondents who had a college education level or above, were employed, and had visited the outpatient Department of Infectious Disease before pregnancy had a significantly higher awareness rate. Previous visits to the Department of Infectious Disease were the only influencing factor for the higher awareness rate (OR =3.108, P=0.049). Conclusions: A lack of knowledge about the transmission route and interruption measures of MTCT of HBV is still common among HBsAg-positive pregnant women. Health education should be directed toward HBsAg-positive mothers to further improve the control of HBV infection.

A Pilot Study of Radiomic Based on Routine CT Reflecting Difference of Cerebral Hemispheric Perfusion.

Background: To explore the effectiveness of radiomics features based on routine CT to reflect the difference of cerebral hemispheric perfusion. Methods: We retrospectively recruited 52 patients with severe stenosis or occlusion in the unilateral middle cerebral artery (MCA), and brain CT perfusion showed an MCA area with deficit perfusion. Radiomics features were extracted from the stenosis side and contralateral of the MCA area based on precontrast CT. Two different region of interest drawing methods were applied. Then the patients were randomly grouped into training and testing sets by the ratio of 8:2. In the training set, ANOVA and the Elastic Net Regression with fivefold cross-validation were conducted to filter and choose the optimized features. Moreover, different machine learning models were built. In the testing set, the area under the receiver operating characteristic (AUC) curve, calibration, and clinical utility were applied to evaluate the predictive performance of the models. Results: The logistic regression (LR) for the triangle-contour method and artificial neural network (ANN) for the semiautomatic-contour method were chosen as radiomics models for their good prediction efficacy in the training phase (AUC = 0.869, 0.873) and the validation phase (AUC = 0.793, 0.799). The radiomics algorithms of the triangle-contour and semiautomatic-contour method were implemented in the whole training set (AUC = 0.870, 0.867) and were evaluated in the testing set (AUC = 0.760, 0.802). According to the optimal cutoff value, these two methods can classify the vascular stenosis side class and normal side class. Conclusion: Radiomic predictive feature based on precontrast CT image could reflect the difference of cerebral hemispheric perfusion to some extent.

Radiomics for predicting revised hematoma expansion with the inclusion of intraventricular hemorrhage growth in patients with supratentorial spontaneous intraparenchymal hematomas.

BACKGROUND: Previous radiomics analyses of hematoma expansion have been based on the traditional definition, which only focused on changes in intraparenchymal volume. However, the ability of radiomics-related models to predict revised hematoma expansion (RHE) with the inclusion of intraventricular hemorrhage expansion remains unclear. To develop and validate a noncontrast computed tomography (NCCT)-based clinical- semantic-radiomics nomogram to identify supratentorial spontaneous intracerebral hemorrhage (sICH) patients with RHE on admission. METHODS: In this double-center retrospective study, data from 376 patients with sICH (training set: n=299; test set: n=77; external validation cohort: n=91) were reviewed. A radiomics model, a clinical-semantic model, and a combined model were then constructed based on the logistic regression machine learning approach. Radiomics features were extracted and selected by least absolute shrinkage and selection operator (LASSO) with 5-fold cross validation. Furthermore, the classical BRAIN scoring system was also constructed to predict RHE. Discriminative performance of the models was evaluated on the training and test set with area under the curve (AUC) and decision curve analysis (DCA). RESULTS: The addition of radiomics to clinical-semantic factors significantly improved the prediction performance of RHE compared with the clinical-semantic model alone in the training (AUC, 0.94 vs. 0.81, P<0.05) and test (AUC, 0.84 vs. 0.71, P<0.05) sets, with similar results in the validation set (AUC, 0.83 vs. 0.69, P<0.05). Moreover, the discrimination efficacy of the BRAIN score was significantly lower than the other 3 models (AUC of 0.71 in the training set, P<0.05). CONCLUSIONS: The clinical-semantic-radiomics combined model had the greatest potential for discriminating RHE, and significantly outperformed the classical BRAIN scoring system.

Automated detection of 3D midline shift in spontaneous supratentorial intracerebral haemorrhage with non-contrast computed tomography using deep convolutional neural networks.

Deep learning (DL)-based convolutional neural networks facilitate more accurate detection and rapid analysis of MLS. Our objective was to assess the feasibility of applying a DL-based convolutional neural network to non-contrast computed tomography (CT) for automated 2D/3D brain midline shift measurement and outcome prediction after spontaneous intracerebral haemorrhage. In this retrospective study, 140 consecutive patients were referred for CT assessment of sICH from January 2014 to April 2019. The level of consciousness of patients was evaluated using the Glasgow Coma Scale (GCS) score, and the Glasgow Outcome Scale (GOS) score was calculated to classify the outcome. The distance of midline shift (MLS-D) and volume of midline shift (MLS-V) were automatically measured via DL methods. Patients were divided into three groups based on GCS scores: mild degree (GCS score: 13-15), moderate degree (GCS score: 9-12), and severe degree (GCS score: 3-8). Spearman's correlation analysis revealed statistically significant (P<0.01) positive correlation between GCS and MLS-D (r=0.709) and MLS-V (r=0.754). The AUC of MLS-V was slightly larger than that of MLS-D (0.831 vs 0.799, P=0.318) in the midline shifting group. The AUC of MLS-V was significantly larger than that of MLS-D (0.854 vs 0.736, P=0.03) in patients with severe degree GCS scores. The DL-based measurements of both MLS-D and MLS-V enable the assessment of consciousness and the prediction of the outcome of sICH. Compared to MLS-D, MLS-V measurement can better indicate mass effect and predict outcomes, particularly in severe cases.

Neuroimaging Anomalies in Community-Dwelling Asymptomatic Adults With Very Early-Stage White Matter Hyperintensity.

White matter hyperintensity (WMH) is common in healthy adults in their 60s and can be seen as early as in their 30s and 40s. Alterations in the brain structural and functional profiles in adults with WMH have been repeatedly studied but with a focus on late-stage WMH. To date, structural and functional MRI profiles during the very early stage of WMH remain largely unexplored. To address this, we investigated multimodal MRI (structural, diffusion, and resting-state functional MRI) profiles of community-dwelling asymptomatic adults with very early-stage WMH relative to age-, sex-, and education-matched non-WMH controls. The comparative results showed significant age-related and age-independent changes in structural MRI-based morphometric measures and resting-state fMRI-based measures in a set of specific gray matter (GM) regions but no global white matter changes. The observed structural and functional anomalies in specific GM regions in community-dwelling asymptomatic adults with very early-stage WMH provide novel data regarding very early-stage WMH and enhance understanding of the pathogenesis of WMH.

Interfacial Mo-N-C Bond Endowed Hydrogen Evolution Reaction on MoSe2@N-Doped Carbon Hollow Nanoflowers.

Molybdenum diselenide (MoSe2) has been considered as promising electrocatalysts for catalyzing the hydrogen evolution reaction (HER) due to its narrow band gap and appropriate adsorption free energy. However, its catalytic performance is still impeded by inferior electrical conductivity and insufficient active sites, thus leading to unsatisfactory HER performance. Herein, MoSe2@N-doped carbon (NC) hollow nanoflowers with interfacial Mo-N-C bonds were controllably fabricated through the in situ selenization of the self-polymerized Mo-polydopamine precursor. Benefiting from the unique hollow structure, NC protective layer, and intimate interfacial interaction, the optimal MoSe2@NC displays good HER performance with low overpotentials (175 and 183 mV) and long-term stability (up to 12 h at -10 mA cm-2) in 0.5 M H2SO4 and 1.0 M KOH solutions, respectively. The theoretical results show that Mo-N-C bonds at the interface of MoSe2@NC give rise to relatively low unoccupied eg orbital density of states and ideal H2 adsorption free energy. This work presented here highlights the critical role of interfacial chemical bonds in regulating the electronic structure of nanomaterials and further improving the HER performance.

2D coordination polymer-derived CoSe2-NiSe2/CN nanosheets: the dual-phase synergistic effect and ultrathin structure to enhance the hydrogen evolution reaction.

The evolution of cost-effective hydrogen evolution reaction (HER) electrocatalysts is of great significance for the development of clean energy. Exploring effective synthesis strategies to optimize the performance of non-noble metal electrocatalysts has always attracted our attention. Herein, ultrathin coordination polymers were used as precursors to controllably synthesize two-dimensional (2D) ultrathin dual-phase transition metal selenide (TMSs)/carbon-nitrogen (CN) composites (CoSe2-NiSe2/CN) by a two-step method (first a low temperature hydrothermal method for selenization, and then high temperature calcination selenization). Benefiting from its large specific surface area (49 m2 g-1), abundant catalytically active sites and synergistic effects, CoSe2-NiSe2/CN can significantly enhance the HER catalytic activity and exhibits good electrocatalytic activity with an overpotential of 150 mV at -10 mA cm-2, and a small Tafel slope of 42 mV dec-1 in an acidic electrolyte for the HER. This work provides a new strategy for optimizing the HER catalytic activity of TMSs by preparing 2D ultrathin dual-phase TMS composite materials.

Accurately Regulating the Electronic Structure of Nix Sey @NC Core-Shell Nanohybrids through Controllable Selenization of a Ni-MOF for pH-Universal Hydrogen Evolution Reaction.

N-doped carbon-encapsulated transition metal selenides (TMSs) have garnered increasing attention as promising electrocatalysts for hydrogen evolution reaction (HER). Accurately regulating the electronic structure of these nanohybrids to reveal the underlying mechanism for enhanced HER performances is still challenging and thus requires deep excavation. Herein, a series of pomegranate-like Nix Sey @NC core-shell nanohybrids (including Ni0.85 Se @ NC, NiSe2 @NC, and NiSe@NC) through controllable selenization of a Ni-MOF precursor is reported. The component of the nanohybrids can be fine-tuned by tailoring the selenization temperature and feed ratio, through which the electronic structure can be synchronously regulated. Among these nanohybrids, the Ni0.85 Se @ NC exhibits the optimum pH-universal HER performance with overpotentials of 131, 135, and 183 mV in 0.5 m H2 SO4 , 1.0 m KOH, and 1.0 m PBS, respectively, at 10 mA cm-2 , which are attributed to the increased partial density of state at the Fermi level and effective van der Waals interactions between Ni0.85 Se and NC matrix explained by density functional theory calculations.

Metal-organic framework templated Pd/CeO2@N-doped carbon for low-temperature CO oxidation.

A new Pd/Ce based metal-organic framework is designed and synthesized as a self-sacrificial template for fabrication of an efficient catalyst for CO oxidation. The catalyst obtained by thermal annealing at 700 °C (Pd/CeO2@NC-700) is composed of N-doped carbon with embedded Pd and CeO2 nanoparticles, which are highly dispersed and closely connected in the N-doped carbon; the high Pd loading (33.7 wt%) and the coupling between Pd and the CeO2 phase synergistically boost the CO oxidation performance. The Pd/CeO2@NC-700 catalyst exhibits a 100% conversion temperature of 89 °C and excellent long-term stability. By combining structural characterization with density functional theory calculations, two possible CO oxidation pathways of TPB and TOP are revealed, in which the adsorbed O2 directly dissociates to O* atoms and activates CO* molecules. The transfer of O* between Pd and Ce (TPB) or Pd and Pd (TOP) facilitates the formation of intermediates and finally results in the production of CO2. This work provides a new insight into the development of novel efficient catalysts for CO oxidation based on metal-organic frameworks.

NiSe2/Ni(OH)2 Heterojunction Composite through Epitaxial-like Strategy as High-Rate Battery-Type Electrode Material.

Constructing heterojunction is a promising way to improve the charge transfer efficiency and can thus promote the electrochemical properties. Herein, a facile and effective epitaxial-like growth strategy is applied to NiSe2 nano-octahedra to fabricate the NiSe2-(100)/Ni(OH)2-(110) heterojunction. The heterojunction composite and Ni(OH)2 (performing high electrochemical activity) is ideal high-rate battery-type supercapacitor electrode. The NiSe2/Ni(OH)2 electrode exhibits a high specific capacity of 909 C g-1 at 1 A g-1 and 597 C g-1 at 20 A g-1. The assembled asymmetric supercapacitor composed of the NiSe2/Ni(OH)2 cathode and p-phenylenediamine-functional reduced graphene oxide anode achieves an ultrahigh specific capacity of 303 C g-1 at 1 A g-1 and a superior energy density of 76.1 Wh kg-1 at 906 W kg-1, as well as an outstanding cycling stability of 82% retention for 8000 cycles at 10 A g-1. To the best of our knowledge, this is the first example of NiSe2/Ni(OH)2 heterojunction exhibiting such remarkable supercapacitor performance. This work not only provides a promising candidate for next-generation energy storage device but also offers a possible universal strategy to fabricate metal selenides/metal hydroxides heterojunctions.

A sulfonated cobalt phthalocyanine/carbon nanotube hybrid as a bifunctional oxygen electrocatalyst.

The development of effective bifunctional catalysts for both oxygen reduction reactions (ORRs) and oxygen evolution reactions (OERs) is crucial for improving the performance of charge and discharge processes in rechargeable metal-air batteries. Here, we report a sulfonated cobalt phthalocyanine/carbon nanotube hybrid (CoPc-SO3H/CNT) prepared by a facile anchoring method along with sonication and magnetic stirring. The resulting CoPc-SO3H/CNT hybrid exhibits better catalytic activity for ORRs and OERs than the cobalt phthalocyanine/carbon nanotube hybrid (CoPc/CNT), sulfonated cobalt phthalocyanine (CoPc-SO3H), cobalt phthalocyanine (CoPc) and the carbon nanotube (CNT). The onset potential of CoPc-SO3H/CNT for the ORR in 0.1 M KOH is 0.88 V (vs. RHE), which is higher than that of CoPc/CNT (0.85 V), the CNT (0.80 V), CoPc-SO3H (0.77 V) and CoPc (0.66 V). Meanwhile, the CoPc-SO3H/CNT hybrid shows a much lower OER potential (1.62 V) at a current density of 10 mA cm-2 compared to CoPc-SO3H (1.64 V), CoPc/CNT (1.74 V), the CNT (1.96 V) and CoPc (>2.00 V) in 1 M KOH. Similar patterns are also found in 0.1 M KOH solution. Both the conductive CNT and the electron-withdrawing sulfonic groups are confirmed to benefit the electrochemical oxygen reactions (ORRs/OERs).

A MOF-derived coral-like NiSe@NC nanohybrid: an efficient electrocatalyst for the hydrogen evolution reaction at all pH values.

A coral-like NiSe@NC nanohybrid as an effective electrocatalyst for the hydrogen evolution reaction (HER) at all pH values, constructed via the in situ selenation of a Ni-MOFs precursor, is reported. The electrocatalyst shows overpotentials of 123 mV, 250 mV and 300 mV in 0.5 M H2SO4, 1.0 M KOH and 1.0 M PBS, respectively, to afford a current density of 10 mA cm-2. Meanwhile, NiSe@NC also exhibits a small Tafel slope and superior long-term stability over a wide pH range. The excellent electrocatalytic performance should be ascribed to the unique coral-like structure with a large BET specific surface area (125.4 m2 g-1) and mesoporous features, as well as synergistic effects between NiSe nanocrystals and highly conductive N-doped porous carbon.

Bimetallic-MOF Derived Accordion-like Ternary Composite for High-Performance Supercapacitors.

Supercapacitors are regarded to be highly probable candidates for next-generation energy storage devices. Herein, a bimetallic Co/Ni MOF is used as a sacrificial template through an alkaline hydrolysis and selective oxidation process to prepare an accordion-like ternary NiCo2O4/ß-Ni xCo1- x(OH)2/α-Ni xCo1- x(OH)2 composite, which is composed of Co/Ni(OH)2 nanosheets with large specific surface as the frame and NiCo2O4 nanoparticles with high conductivity as the insertion, for supercapacitor application. This material exhibits both high specific capacitance (1315 F·g-1 at 5 A·g-1) and excellent cycle performance (retained 90.7% after 10 000 cycles). This hydrolysis-oxidation process, alkali hydrolysis followed by oxidation with H2O2, offers a novel approach to fabricate the Ni/Co-based electrode materials with enhanced supercapacitor performance.

Comparison of two water oxidation electrocatalysts by copper or zinc supermolecule complexes based on porphyrin ligand.

Based on the 5,10,15,20-tetra(cyanophenyl)porphyrin (CNTCPP) ligand, two supermolecule complexes formulated as [Cu(CNTCPP)]·2DMF (Cu-CNTCPP) and [Zn(CNTCPP)] (Zn-CNTCPP) have been synthesized and structurally characterized by single-crystal X-ray diffraction. Cu-CNTCPP features a 0 dimensional (0D) supramoleculer structure, whereas Zn-CNTCPP is a 2D structure. With coordination unsaturated points, Cu-CNTCPP exhibits electrocatalytic activity toward oxygen evolution reaction (OER) with low potential in 1.0 M KOH, generating a current density of 10 mA cm-2 at an potential of 1.66 V vs. RHE, which means it an efficient electrocatalytic material for OER.