HIF-1α serves as a co-linker between AD and T2DM.

Alzheimer's disease (AD)-related brain deterioration is linked to the type 2 diabetes mellitus (T2DM) features hyperglycemia, hyperinsulinemia, and insulin resistance. Hypoxia as a common risk factor for both AD and T2DM. Hypoxia-inducible factor-1 alpha (HIF-1α) acts as the main regulator of the hypoxia response and may be a key target in the comorbidity of AD and T2DM. HIF-1α expression is closely related to hyperglycemia, insulin resistance, and inflammation. Tissue oxygen consumption disrupts HIF-1α homeostasis, leading to increased reactive oxygen species levels and the inhibition of insulin receptor pathway activity, causing neuroinflammation, insulin resistance, abnormal Aß deposition, and tau hyperphosphorylation. HIF-1α activation also leads to the deposition of Aß by promoting the abnormal shearing of amyloid precursor protein and inhibiting the degradation of Aß, and it promotes tau hyperphosphorylation by activating oxidative stress and the activation of astrocytes, which further exasperates AD. Therefore, we believe that HIF-α has great potential as a target for the treatment of AD. Importantly, the intracellular homeostasis of HIF-1α is a more crucial factor than its expression level.

Emerging transition metal and carbon nanomaterial hybrids as electrocatalysts for water splitting: a brief review.

Electrocatalytic water splitting has appeared to be a sustainable green technology for hydrogen and oxygen production, and noble metal-based electrocatalysts, like Pt for hydrogen evolution reaction (HER) and RuO2/IrO2 for oxygen evolution reaction (OER) have been proved to be state-of-the-art in water electrolyzers. However, high cost and scarcity of noble metals hinder large-scale applications of these electrocatalysts in practical commercial water electrolyzers. As an alternative, transition metal based electrocatalysts have attracted great attention because of the exciting catalytic performance, cost-effectiveness and abundant availability. However, their long-term stability in water splitting devices is unsatisfactory because of agglomeration and dissolution in the harsh operating environment. A possible solution to this issue is encapsulating transition metal (TM) based materials in stable and highly conductive carbon nanomaterials (CNMs) to make a hybrid of TM/CNMs, and the performance of TM/CNMs could be further enhanced by heteroatom (N-, B-, and dual N,B-) doping to carbon network in CNMs to break the carbon electroneutrality due to the different electronegativity, modulate the electronic structure to facilitate the adsorption of reaction intermediates, and promotion of efficient electron transfer to enhance the number of catalytically active sites for water splitting operation. In this review article, the recent progress of TM-based materials hybridizing with CNMs, N-CNMs, B-CNMs, and N,B-CNMs as electrocatalysts towards HER, OER as well as overall water splitting have been summarized, and the challenges and future prospects are also discussed.

Modulating Electronic Structure with Copper Doping to Promote the Electrocatalytic Performance of Cobalt Disulfide in Li-O2 Batteries.

Introducing heteroatom into catalyst lattice to modulate its intrinsic electronic structure is an efficient strategy to improve the electrocatalytic performance in Li-O2 batteries. Herein, Cu-doped CoS2 (Cu-CoS2 ) nanoparticles are fabricated by a solvothermal method and evaluated as promising cathode catalysts for Li-O2 batteries. Based on physicochemical analysis as well as density functional theory calculations, it is revealed that doping Cu heteroatom in CoS2 lattice can increase the covalency of the CoS bond with more electron transfer from Co 3d to S 3p orbitals, thereby resulting in less electron transfer from Co 3d to O 2p orbitals of Li-O species, which can weaken the adsorption strength toward Li-O intermediates, decrease the reaction barrier, and thus improve the catalytic performance in Li-O2 batteries. As a result, the battery using Cu-CoS2 nanoparticles in the cathode exhibits superior kinetics, reversibility, capacity, and cycling performance, as compared to the battery based on CoS2 catalyst. This work provides an atomic-level insight into the rational design of transition-metal dichalcogenide catalysts via regulating the electronic structure for high-performance Li-O2 batteries.

Multifunctional Catalyst CuS for Nonaqueous Rechargeable Lithium-Oxygen Batteries.

Copper sulfide with flower-like (f-CuS) and carambola-like (c-CuS) morphologies was successfully synthesized by a facile one-step solvothermal route with different surfactants. When employed as cathode catalysts for lithium-oxygen batteries (LOBs), f-CuS outperforms c-CuS in terms of oxygen electrochemistry, judging from the faster kinetics and the higher reversibility of oxygen reduction/oxidation reactions, as well as the better LOB performance. Moreover, an abnormal high-potential discharge plateau was observed in the discharge profile of the LOB. To understand the different performances of f-CuS and c-CuS and the abnormal high-potential plateau, theoretical calculations were conducted, based on which a mechanism was proposed and verified with experiments. On the whole, CuS can work as a multifunctional catalyst for promoting LOB performance, which means that the dissolved CuS in LiTFSI/TEGDME electrolyte can serve as a liquid catalyst by the redox couples of Cu(TFSI)2/Cu(TFSI)2-/Cu(TFSI)22-, in addition to the function as a traditional solid catalyst in the cathode.

One-Step Solvothermal Route to Sn4P3-Reduced Graphene Oxide Nanohybrids as Cycle-Stable Anode Materials for Sodium-Ion Batteries.

Sn4P3, owing to its high theoretical volumetric capacity, good electrical conductivity, and relatively appropriate potential plateau, has been recognized as an ideal anode for sodium-ion batteries (NIBs). However, the current synthetic routes for Sn4P3-based nanohybrids typically involve foreign-template-based multistep procedures, limiting their large-scale production and applications in NIBs. Using commercial red phosphorus as the phosphorus source and nontoxic ethanolamine as the solvent, we herein report a facile and scalable solvothermal protocol for the one-step preparation of Sn4P3-reduced oxide graphene (denoted as Sn4P3-rGO) hybrid materials. Benefiting from the novel strategy and elaborate design, ultrasmall Sn4P3 nanoparticles (2.7 nm on average) are homogeneously anchored onto rGO. The high conductivity of the rGO network and the short electron/ion diffusion path of ultrasmall Sn4P3 nanoparticles give the Sn4P3-rGO hybrid high capacities and stable long-term cyclability. Specifically, the optimized Sn4P3-rGO hybrid displays a remarkable reversible capacity of 663.5 mA h g-1 at a current density of 200 mA g-1, ultralong-term cycle life (301 mA h g-1 after 2500 cycles at a high current density of 2000 mA g-1), and excellent rate capability, presenting itself as a highly promising anode material for NIBs.

High temperature proton exchange membrane fuel cells: progress in advanced materials and key technologies.

High temperature proton exchange membrane fuel cells (HT-PEMFCs) are one type of promising energy device with the advantages of fast reaction kinetics (high energy efficiency), high tolerance to fuel/air impurities, simple plate design, and better heat and water management. They have been expected to be the next generation of PEMFCs specifically for application in hydrogen-fueled automobile vehicles and combined heat and power (CHP) systems. However, their high-cost and low durability interposed by the insufficient performance of key materials such as electrocatalysts and membranes at high temperature operation are still the challenges hindering the technology's practical applications. To develop high performance HT-PEMFCs, worldwide researchers have been focusing on exploring new materials and the related technologies by developing novel synthesis methods and innovative assembly techniques, understanding degradation mechanisms, and creating mitigation strategies with special emphasis on catalysts for oxygen reduction reaction, proton exchange membranes and bipolar plates. In this paper, the state-of-the-art development of HT-PEMFC key materials, components and device assembly along with degradation mechanisms, mitigation strategies, and HT-PEMFC based CHP systems is comprehensively reviewed. In order to facilitate further research and development of HT-PEMFCs toward practical applications, the existing challenges are also discussed and several future research directions are proposed in this paper.

ZIF67@MFC-Derived Co/N-C@CNFs Interconnected Frameworks with Graphitic Carbon-Encapsulated Co Nanoparticles as Highly Stable and Efficient Electrocatalysts for Oxygen Reduction Reactions.

Development of nonprecious metal catalysts for oxygen reduction reaction (ORR) to reduce or eliminate Pt-based electrocatalysts is of great importance for fuel cells. Herein, Co/N-codoped carbon with carbon nanofiber (CNF) interconnected three-dimensional (3D) frameworks and graphitic carbon-encapsulated Co nanoparticles were designed and successfully prepared via the in situ growth of zeolitic imidazolate framework-67 (ZIF67) with biomass nano-microfibrillar cellulose (MFC) and then pyrolysis. The catalyst (Co/N-C@CNFs) exhibited outstanding long-term catalytic durability with 92.7% current retention after 70 000 s, which was much higher than that of commercial Pt/C in alkaline media. The support and connection of CNFs to Co/N-C frameworks and the protection of Co nanoparticles by graphite layers contribute to their impressive long-term catalytic stability. Meanwhile, Co/C-N@CNFs displayed excellent ORR catalytic performance (E0 = 0.952 V vs RHE, E1/2 = 0.852 V vs RHE, and n: 4.2) in alkaline media. This strategy provides new insights into developing advanced nonprecious metal carbon-based catalysts for ORR.

A core-shell structure of polydopamine-coated phosphorus-carbon nanotube composite for high-performance sodium-ion batteries.

The electrochemical performance of red phosphorus is severely limited by its low electrical conductivity and large-volume-expansion-induced material pulverization and continuous solid electrolyte interphase (SEI) growth. Conductive coating has been regarded as an ideal approach to address these issues. In this paper, we design a rational strategy to improve the sodium storage performance of red phosphorus by in situ coating of a polydopamine layer on phosphorus-carbon nanotube hybrid (P-CNT@PD) via a self-polymerization of dopamine under weak base conditions. The in situ generated PD coating can provide an elastic buffer for accommodating the volume change of active materials and prevent their direct contact with the electrolyte. Due to the conductive and elastic PD coating, the P-CNT@PD composite presents a high rate capacity (1060 mA h g-1 at the second discharge and 730 mA h g-1 after 2000 cycles at 2.6 A g-1) and excellent cycling stability (470 mA h g-1 after 5000 cycles at 5.2 A g-1) as an anode for sodium ion batteries. This facile and scalable synthesis route provides a favorable approach for the mass production of high performance electrodes for sodium ion batteries.

NiMn2O4 as an efficient cathode catalyst for rechargeable lithium-air batteries.

NiMn2O4 with different crystal structures was successfully synthesized and evaluated as a cathode catalyst for rechargeable Li-air batteries for the first time. The result reveals that the intermediate spinel structure between normal and inverse spinels demonstrates faster kinetics towards ORR/OER than the normal spinel, leading to a better battery performance.

Inspired by Stenocara Beetles: From Water Collection to High-Efficiency Water-in-Oil Emulsion Separation.

Inspired by the water-collecting mechanism of the Stenocara beetle's back structure, we prepared a superhydrophilic bumps-superhydrophobic/superoleophilic stainless steel mesh (SBS-SSM) filter via a facile and environmentally friendly method. Specifically, hydrophilic silica microparticles are assembled on the as-cleaned stainless steel mesh surface, followed by further spin-coating with a fluoropolymer/SiO2 nanoparticle solution. On the special surface of SBS-SSM, attributed to the steep surface energy gradient, the superhydrophilic bumps (hydrophilic silica microparticles) are able to capture emulsified water droplets and collect water from the emulsion even when their size is smaller than the pore size of the stainless steel mesh. The oil portion of the water-in-oil emulsion therefore permeates through pores of the superhydrophobic/superoleophilic mesh coating freely and gets purified. We demonstrated an oil recovery purity up to 99.95 wt % for surfactant-stabilized water-in-oil emulsions on the biomimetic SBS-SSM filter, which is superior to that of the traditional superhydrophobic/superoleophilic stainless steel mesh (S-SSM) filter lacking the superhydrophilic bump structure. Together with a facile and environmentally friendly coating strategy, this tool shows great application potential for water-in-oil emulsion separation and oil purification.

A SnO2-Based Cathode Catalyst for Lithium-Air Batteries.

SnO2 and SnO2@C have been successfully synthesized with a simple hydrothermal procedure combined with heat treatment, and their performance as cathode catalysts of Li-air batteries has been comparatively evaluated and discussed. The results show that both SnO2 and SnO2@C are capable of catalyzing oxygen reduction reactions (ORR) and oxygen evolution reactions (OER) at the cathode of Li-air batteries, but the battery with SnO2@C displays better performance due to its unique higher conductivity, larger surface area, complex pore distribution, and huge internal space.

Novel nanowire-structured polypyrrole-cobalt composite as efficient catalyst for oxygen reduction reaction.

A novel nanowire-structured polypyrrole-cobalt composite, PPy-CTAB-Co, is successfully synthesized with a surfactant of cetyltrimethylammounium bromide (CTAB). As an electro-catalyst towards oxygen reduction reaction (ORR) in alkaline media, this PPy-CTAB-Co demonstrates a superior ORR performance when compared to that of granular PPy-Co catalyst and also a much better durability than the commercial 20 wt% Pt/C catalyst. Physiochemical characterization indicates that the enhanced ORR performance of the nanowire PPy-CTAB-Co can be attributed to the high quantity of Co-pyridinic-N groups as ORR active sites and its large specific surface area which allows to expose more active sites for facilitating oxygen reduction reaction. It is expected this PPy-CTAB-Co would be a good candidate for alkaline fuel cell cathode catalyst.

Novel Flower-like Nickel Sulfide as an Efficient Electrocatalyst for Non-aqueous Lithium-Air Batteries.

In this paper, metal sulfide materials have been explored for the first time as a new choice of bifunctional cathode electrocatalyst materials for non-aqueous lithium-air batteries (LABs). Nickel sulfides with two different morphologies of flower-like (f-NiS) and rod-like (r-NiS) are successfully synthesized using a hydrothermal method with and without the assistance of cetyltrimethyl ammonium bromide. As LAB cathode catalysts, both f-NiS and r-NiS demonstrate excellent catalytic activities towards the formation and decomposition of Li2O2, resulting in improved specific capacity, reduced overpotentials and enhanced cycling performance when compared to those of pure Super P based electrode. Moreover, the morphology of NiS materials can greatly affect LAB performance. Particularly, the f-NiS is more favorable than r-NiS in terms of their application in LABs. When compared to both r-NiS and pure super P materials as LAB cathode materials, this f-NiS catalyst material can give the highest capacity of 6733 mA h g(-1) and the lowest charge voltage of 4.24 V at the current density of 75 mA g(-1) and also exhibit an quite stable cycling performance.

The double perovskite oxide Sr2CrMoO(6-δ) as an efficient electrocatalyst for rechargeable lithium air batteries.

A double perovskite oxide Sr2CrMoO6-δ (SCM), synthesized using the sol-gel and annealing method with the assistance of citric acid and ethylene diamine tetraacetic acid, was investigated for the first time as an efficient catalyst for rechargeable lithium air batteries. The SCM cathode enables higher specific capacity, lower overpotential and a much better cyclability compared to the pure Super P electrode owing to its excellent electrocatalytic activity towards the formation/decomposition of Li2O2.

Effects of cobalt precursor on pyrolyzed carbon-supported cobalt-polypyrrole as electrocatalyst toward oxygen reduction reaction.

A series of non-precious metal electrocatalysts, namely pyrolyzed carbon-supported cobalt-polypyrrole, Co-PPy-TsOH/C, are synthesized with various cobalt precursors, including cobalt acetate, cobalt nitrate, cobalt oxalate, and cobalt chloride. The catalytic performance towards oxygen reduction reaction (ORR) is comparatively investigated with electrochemical techniques of cyclic voltammogram, rotating disk electrode and rotating ring-disk electrode. The results are analyzed and discussed employing physiochemical techniques of X-ray diffraction, transmission electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, inductively coupled plasma, elemental analysis, and extended X-ray absorption fine structure. It shows that the cobalt precursor plays an essential role on the synthesis process as well as microstructure and performance of the Co-PPy-TsOH/C catalysts towards ORR. Among the studied Co-PPy-TsOH/C catalysts, that prepared with cobalt acetate exhibits the best ORR performance. The crystallite/particle size of cobalt and its distribution as well as the graphitization degree of carbon in the catalyst greatly affects the catalytic performance of Co-PPy-TsOH/C towards ORR. Metallic cobalt is the main component in the active site in Co-PPy-TsOH/C for catalyzing ORR, but some other elements such as nitrogen are probably involved, too.

Improved performance of proton exchange membrane fuel cells with p-toluenesulfonic acid-doped co-PPy/C as cathode electrocatalyst.

A novel catalyst, Co-PPy-TsOH/C, for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs) was prepared by pyrolyzing cobalt salt and p-toluenesulfonic acid (TsOH)-doped polypyrrole-modified carbon support in an inert atmosphere. The characteristics and electrocatalytic activities of Co-PPy-TsOH/C were analyzed with various techniques, including Raman spectroscopy, elemental analysis, rotating ring disk electrode analysis, and a single H(2)-O(2) PEMFC, and compared with those of undoped catalyst Co-PPy/C. The results showed that doping TsOH introduces larger N and S contents in Co-PPy-TsOH/C, leading to much better electrocatalytic performance for ORR than Co-PPy/C, and that Co-PPy-TsOH/C is more likely to follow a four-electron-transfer reaction to reduce oxygen directly to H(2)O. The performance of PEMFCs with Co-PPy-TsOH/C as cathode catalyst is better than that with Co-PPy/C, and the resulting maximum output power density of 203 mW cm(-2) is a substantial improvement over the best values reported in the literature with Co-PPy/C-based cathode catalyst. This implies that doping TsOH is a valuable method to improve the catalytic activity of Co-PPy/C and that Co-PPy-TsOH/C is a promising cathode catalyst for PEMFCs. The function and mechanism of doping have also been analyzed and the configurations of PPy-TsOH/C and Co-PPy-TsOH/C proposed.