Amorphous quaternary alloy nanoplates for efficient catalysis of hydrogen evolution reaction

Developing a highly efficient non-precious transition metal-based electrocatalyst via a facile approach toward the hydrogen evolution reaction (HER) is critical for large-scale hydrogen production but still remains challenging. Herein, a cost-effective electrochemical deposition strategy is rationally proposed to construct amorphous quaternary FeCoNiCu alloy nanosheets supported on nickel foam (NF) towards this challenge. Benefiting from the synergistic effect of multi-metal atoms interaction and the high exposure of active sites caused by abundant open voids, the as-synthesized FeCoNiCu/NF electrode exhibits high catalytic activity and robustness toward HER in alkaline solution, requiring an overpotential of only 35 mV to reach a current density of 10 mA cm–2. This study may pave a new avenue to design advanced electrocatalyst for energy conversion

Activating TiO₂ through the Phase Transition-Mediated Hydrogen Spillover to Outperform Pt for Electrocatalytic pH-Universal Hydrogen Evolution.

Endowing conventional materials with specific functions that are hardly available is invariably of significant importance but greatly challenging. TiO2 is proven to be highly active for the photocatalytic hydrogen evolution while intrinsically inert for electrocatalytic hydrogen evolution reaction (HER) due to its poor electrical conductivity and unfavorable hydrogen adsorption/desorption behavior. Herein, the first activation of inert TiO2 for electrocatalytic HER is demonstrated by synergistically modulating the positions of d-band center and triggering hydrogen spillover through the dual doping-induced partial phase transition. The N, F co-doping-induced partial phase transition from anatase to rutile phase in TiO2 (AR-TiO2|(N,F)) exhibits extraordinary HER performance with overpotentials of 74, 80, and 142 mV at a current density of 10 mA cm-2 in 1.0 M KOH, 0.5 M H2SO4, and 1.0 M phosphate-buffered saline electrolytes, respectively, which are substantially better than pure TiO2, and even superior to the benchmark Pt/C catalysts. These findings may open a new avenue for the development of low-cost alternative to noble metal catalysts for electrocatalytic hydrogen production

Core-shell SiC/SiO2 heterostructures in nanowires

This paper presents a simple vapour deposition method for one-step synthesis of SiC//SiO2 core-shell heterostructured nanowires. The phases, structures and morphologies of the synthesized core-shell heterostructures are systemically studied by field emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and high-resolution transmission electron microscopy. The results show that these heterostructures consist of a single crystalline SiC core of 20∼30 nm diameter covered by a uniform layer, about 15 nm thickness of amorphous SiO2. Such heterostructures were grown based on the vapour–solid mechanism and the deposition way has an important influence on their morphology. A unique optical property has also been found in their photoluminescence spectra that have blue shift relative to the bulk SiC

Metal-organic framework-derived nanocomposites for electrocatalytic hydrogen evolution reaction

The rapid development of hydrogen energy is strongly dependent on the economic and efficient production of hydrogen. The electrocatalytic splitting of water to molecular hydrogen via the hydrogen evolution reaction (HER) provides an appealing solution for producing high-purity hydrogen, but low-cost and highly active electrocatalysts are required for HER. Among currently investigated HER electrocatalysts, metal-organic framework (MOF)-derived nanocomposites constructed from transition metals (TMs)/TM compounds (TMCs) and carbon materials offer extremely promising and attractive HER activities because of their unique properties, such as tunable compositions, readily regulated electronic structures, controllable morphologies, and diverse configuration. Herein, this article provides a comprehensive overview of MOF-derived nanocomposites as HER electrocatalysts for water splitting. It begins with the introduction of the fundamentals of electrocatalytic HER. Afterwards, several ingeniously designed strategies for improved MOF-derived HER electrocatalysts are meticulously summarized and discussed, with special emphasis on the component manipulation of the TMs/TMCs, carbon matrix modifications, morphology tuning and electrode configuration engineering. Finally, future perspectives on the development of these nanocomposites as HER electrocatalysts are proposed.This work was financially supported by the National Natural Science Foundation of China (Grant Nos. 51672049, 51871060, 51727801 and 51831009), Research Grant for Talent Introduction of Fudan University, China (Grant No. JJH2021103), the China Postdoctoral Science Foundation (Grant No. 2018M640337 and 2019T120301), the Recruitment Program of Global Youth Experts and Fudan’s Undergraduate Research Opportunities Program, FDUROP

NiS1−xSex Nanoparticles Anchored on Nitrogen-Doped Reduced Graphene Oxide as Highly Stable Anode for Sodium-Ion Battery

Nickel sulfides are regarded as one of the promising anode materials for sodium-ion batteries (SIBs), but the sluggish electrodes kinetics and rapid capacity decay, caused by their intrinsic low electrical conductivity and high bulk expansion, greatly limit their practical application. To overcome these obstacles, nano-sized, selenium-doped, nickel sulfide particles, anchored on nitrogen-doped reduced graphene oxide composites (NiS1−xSex@N–rGO), are rationally synthesized. The broad Na+ diffusion channels, resulting from Se doping, as well as the short Na+ transferring path, attributed from nano-size scale of NiS1−xSex particles, endow NiS1−xSex@N–rGO composites with ultrafast storage kinetics. Moreover, strong coupled effect between the NiS1−xSex and N–rGO is beneficial to the uniform dispersion of NiS1−xSex nanoparticles, improving electrical conductivity and suppressing the volume variation in charge/discharge process. Furthermore, the cut-off discharge voltage is modulated to realize the smaller volume change during cycle process. As a result, the fabricated anode of SIBs based on NiS1−xSex@N–rGO composites exhibits a high specific capacity of 300 mAh g−1, at the current density of 1 A g−1, after 1000 cycles with almost no capacity degradation

MicroRNA‐215‐5p promotes proliferation, invasion, and inhibits apoptosis in liposarcoma cells by targeting MDM2

Abstract Background Liposarcoma (LPS) is one of the most common soft tissue malignancies in adults, and it is characterized by dysregulation of multiple signaling pathways, including MDM2 proto‐oncogene (MDM2) amplification. MicroRNA (miRNA) regulates gene expression through incomplete complementary pairing with the 3' untranslated region of mRNAs involved in tumor progression. Methods In this study, bioinformatics analysis, RT‐qPCR, dual‐luciferase reporter gene, MTT, flow cytometry, cell scratches, chamber migration, colony formation, FISH, WB, and CCK8 were used. Results RT‐qPCR showed that the expression of MDM2 was increased when miR‐215‐5p was overexpressed compared with the control group. The dual‐luciferase reporter gene showed that the Renilla ratio firefly fluorescence intensity was decreased in the overexpression group compared with the control group. Cell phenotype experiments revealed that the overexpression group had increased cell proliferation rate, increased apoptosis rate, increased colony formation rate, increased cell healing area ratio, and increased number of cell invasions. FISH revealed increased MDM2 expression in the overexpression group. WB suggested decreased Bax expression, increased PCNA, Bcl‐2, and MDM2 expression, and decreased P53 and P21 expression in the overexpression group. Conclusions In this study, we suggest that miR‐215‐5p can target and promote MDM2 expression, promote the proliferation and invasion of LPS cells SW‐872, and inhibit apoptosis.Targeting miR‐215‐5p may be a novel therapeutic strategy for the treatment of LPS

Feasibility Analysis and Clinical Applicability of a Modified Type V Resection Method for Malignant Bone Tumors of the Proximal Humerus

Objective: The purpose of this study was to explore the feasibility and clinical applicability of a modified type V resection method for malignant bone tumors of the proximal humerus. Methods: The relevant anatomic MRI data from 30 normal adult shoulder joints were measured to analyze the feasibility of the modified type V resection method for malignant bone tumors of the proximal humerus. Sixteen patients with malignant bone tumors of the proximal humerus were treated with modified radical resection between March 2012 and April 2017. Recurrence of tumor was evaluated after surgery, and shoulder function was assessed according to the Enneking skeletal muscle tumor function scoring system. Results: Radiographic results showed that the modified type V resection method was feasible, and within the allowable range of the maximum longitudinal diameter (<29.8 mm) and depth (<4 mm). Surgery was successfully completed in all 16 cases, and pathological examination suggested that the purposes for radical resection had been achieved. All patients were followed up over 3–49 months (mean, 15.6 months). One patient had local recurrence at 12 months after surgery, and we performed upper limb amputation. The remaining 15 patients had good prosthesis survival. At the final follow-up, shoulder joint function had recovered compared with preoperative levels, with a mean Enneking score of 25.8 points (range, 24–27 points). Conclusion: Modified type V resection may be feasible for treating tumors of the proximal humerus, maintaining good early shoulder function

Porous Spinel ZnxCo3–xO4 Hollow Polyhedra Templated for High-Rate Lithium-Ion Batteries

Nanostructured metal oxides with both anisotropic texture and hollow structures have attracted considerable attention with respect to improved electrochemical energy storage and enhanced catalytic activity. While synthetic strategies for the preparation of binary metal oxide hollow structures are well-established, the rational design and fabrication of complex ternary metal oxide with nonspherical hollow features is still a challenge. Herein, we report a simple and scalable strategy to fabricate highly symmetric porous ternary ZnxCo3–xO4 hollow polyhedra composed of nanosized building blocks, which involves a morphology-inherited and thermolysis-induced transformation of heterobimetallic zeolitic imidazolate frameworks. When tested as anode materials for lithium-ion batteries, these hollow polyhedra have exhibited excellent electrochemical performance with high reversible capacity, excellent cycling stability, and good rate capability.ASTAR (Agency for Sci., Tech. and Research, S’pore

Growth of tapered SiC nanowires on flexible carbon fabric : toward field emission applications

Tapered silicon carbide (SiC) nanowires were directly grown on the surface of flexible carbon fabric by a chemical vapor deposition process. The products were systemically characterized by X-ray diffraction, field emission scanning electron microscopy, high-resolution transmission electron microscopy, selected area electronic diffraction, and energy-dispersive X-ray spectroscopy. The results revealed that the tapered nanowires were of single crystalline β-SiC phase with the growth direction along [111] and had a feature of zigzag faceting over the wire surfaces. Such faceting was created by a quasi-periodic placement of twinning boundaries along the wire axis, which can be explained by surface energy minimization during the growth process. Based on the characterizations and thermodynamics analysis, the Fe-assisted vapor–liquid–solid (VLS) growth mechanism of tapered SiC nanowires was discussed. Furthermore, field emission measurements showed a very low turn-on field at 1.2 V μm–1 and a high field-enhancement factor of 3368. This study shows that SiC nanowires on carbon fabric have potential applications in electronic devices and flat panel displays