Single-atom Mn sites confined into hierarchically porous core-shell nanostructures for improved catalysis of oxygen reduction.

Applications of zinc-air batteries are partially limited by the slow kinetics of oxygen reduction reaction (ORR); Thus, developing effective strategies to address the compatibility issue between performance and stability is crucial, yet it remains a significant challenge. Here, we propose an in situ gas etching-thermal assembly strategy with an in situ-grown graphene-like shell that will favor Mn anchoring. Gas etching allows for the simultaneous creation of mesopore-dominated carbon cores and ultrathin carbon layer shells adorned entirely with highly dispersed Mn-N4 single-atom sites. This approach effectively resolves the compatibility issue between activity and stability in a single step. The unique core-shell structure allows for the full exposure of active sites and effectively prevents the agglomerations and dissolution of Mn-N4 sites in cores. The corresponding half-wave potential for ORR is up to 0.875 V (vs. reversible hydrogen electrode (RHE)) in 0.1 M KOH. The gained catalyst (Mn-N@Gra-L)-assembled zinc-air battery has a high peak power density (242 mW cm-2) and a durability of âˆ¼ 115 h. Furthermore, replacing the zinc anode achieved a stable cyclic discharge platform of âˆ¼ 20 h at varying current densities. Forming more fully exposed and stable existing Mn-N4 sites is a governing factor for improving the electrocatalytic ORR activity, significantly cycling durability, and reversibility of zinc-air batteries.

Unraveling the Electron Transfer Effect of Single-Metal Ce-N4 Sites via Mesopore-Coupling for Boosted Oxygen Reduction Activity.

The development of cerium (Ce) single-atom (SA) electrocatalysts for oxygen reduction reaction (ORR) with high active-site utilization and intrinsic activity has become popular recently but remains challenging. Inspired by an interesting phenomenon that pore-coupling with single-metal cerium sites can accelerate the electron transfer predicted by density functional theory calculations, here, a facile strategy is reported for directional design of a highly active and stable Ce SA catalyst (Ce SA/MC) by the coupling of single-metal Ce-N4 sites and mesopores in nanocarbon via pore-confinement-pyrolysis of Ce/phenanthroline complexes combined with controlling the formation of Ce oxides. This catalyst delivers a comparable ORR catalytic activity with a half-wave potential of 0.845 V versus RHE to the Pt/C catalyst. Also, a Ce SA/MC-based zinc-air battery (ZAB) has exhibited a higher energy density (924 Wh kgZn -1 ) and better long-term cycling durability than a Pt/C-based ZAB. This proposed strategy may open a door for designing efficient rare-earth metal catalysts with single-metal sites coupling with porous structures for next-generation energy devices.

Bioinspired Hydrophobicity Coupled with Single Fe-N4 Sites Promotes Oxygen Diffusion for Efficient Zinc-Air Batteries.

The poor oxygen diffusion and sluggish oxygen reduction reaction (ORR) kinetics at multiphase interfaces in the cathode suppress the practical application of zinc-air batteries. Developing effective strategies to tackle the issue is of great significance for overcoming the performance bottleneck but remains challenging. Here, a multiscale hydrophobic surface is designed on the iron single-atom catalyst via a gas-phase fluorination-assisted method inspired by the structure of gas-trapping mastoids on lotus leaves. The hydrophobic Fe-FNC attains a higher peak power density of up to 226 mW cm-2 , a long durability of up close to 140 h, and better cyclic durability of up to 300 cycles compared to the corresponding Pt/C-based Zn-air battery. Experiments and theoretical calculations indicate that the formed more triple-phase interfaces and exposed isolated Fe-N4 sites are proposed as the governing factors in boosting electrocatalytic ORR activity and remarkable cycling durability for Zn-air batteries.

Succulent-plant-like Ni-Co alloy efficient catalysts for direct borohydride fuel cells.

A Ni-Co alloy catalyst with a unique succulent-plant-like morphology is prepared by a simple electrodeposition method, while the effects of deposition conditions on its performance are also investigated systematically. The research results show that the Ni0.889-Co0.111 catalyst exhibits excellent activity, selectivity, and stability to the borohydride oxidation reaction. Moreover, when Ni0.889-Co0.111 is assembled as the anode catalyst, the direct borohydride fuel cell delivers a peak power density of 490 mW cm-2 and an open-circuit voltage of 1.87 V at 343 K and can run stably for dozens of hours. The significant improvement in Ni-Co catalyst performance can be attributed to its unique succulent-plant-like morphology and the introduction of an appropriate amount of Co.

Porous Ni-Cu Alloy Dendrite Anode Catalysts with High Activity and Selectivity for Direct Borohydride Fuel Cells.

A porous Ni-Cu alloy dendrite catalyst covered by Ni nanoparticles (Ni-np@NC) has been fabricated by an ultrafast and controllable strategy. The research results show that the morphology of the Ni-Cu alloy depends strongly on the Cu2+concentration. Moreover, the Ni-np@NC catalyst demonstrates excellent selectivity and activity toward the borohydride oxidation reaction (BOR). Furthermore, on the Ni-np@NC catalyst electrode, the overpotential merely requires 169 mV at a current density of 10 mA cm-2 for BOR, and the fuel efficiency may reach 70%. The direct borohydride fuel cell using the Ni-np@NC/C anode can export a maximum power density of 218 mW cm-2, much higher than that using the noble-based anode reported in the literature. The remarkable enhancement of Ni-np@NC catalyst performances is on the back of the unique morphology of porous dendrite covered by nanoparticles and the introduction of Cu.

An efficient Ni-P amorphous alloy electrocatalyst with a hierarchical structure toward borohydride oxidation.

Nickel has been widely researched in the electrooxidation of borohydride due to its low cost and abundant reserves, but its catalytic activity and stability need to be improved for practical application. In this work, a Ni and P deposited nickel foam (Ni-P@NF) catalyst electrode with a unique hierarchical structure is prepared by a simple one-step electrodeposition method. The structure, morphology, and catalytic performances of Ni-P@NF are investigated systematically. The results show that Ni-P@NF exhibits excellent catalytic activity, stability, and durability during borohydride electrooxidation. On the Ni-P@NF catalyst electrode, the current density for borohydride oxidation can reach 225 mA cm-2; the fuel utilization is up to 84% and 97% of the initial current is maintained even after 500 cycles of cyclic voltammetry (CV), while a traditional H-type direct sodium borohydride fuel cell (DBFC) assembled with a Ni-P@NF catalyst anode can deliver a maximum power density of 52.5 mW cm-2 and an open circuit potential of 1.87 V. These merits can be attributed to the unique hierarchical structure of the Ni-P catalyst and the introduction of phosphorus. The results also show that the Ni-P@NF catalyst has certain application potential in DBFCs.

The Herbal Formula Granule Prescription Mahuang Decoction Ameliorated Chronic Kidney Disease Which Was Associated with Restoration of Dysbiosis of Intestinal Microbiota in Rats.

Chronic kidney disease (CKD) has become a global health issue, and there is increasing evidence showing the beneficial roles of traditional Chinese medicine (TCM) in CKD treatment. Here, we studied the renoprotective role of Mahuang decoction, a famous TCM prescription, in a rat CKD model induced with the combination of doxorubicin and adenine. Our data showed that intragastric administration of Mahuang decoction inhibited the loss of bodyweight and attenuated proteinuria, serum creatinine, and blood urea nitrogen in CKD rats. Kidney histological analysis revealed decreased tubulointerstitial injury and fibrosis in CKD rats treated with Mahuang decoction accompanied with suppressed expression of TGF-ß1 and phosphorylated NF-κB/P65 (p-P65) as indicated by immunohistochemistry. ELISA analysis demonstrated reduced serum levels of proinflammatory cytokines TNFα and IL-6. Most importantly, intestinal microbiota analysis by 16s rRNA-seq showed that Mahuang decoction restored the impaired richness and diversity of intestinal microflora and recovered the disrupted microbial community through reducing the abundance of deleterious microbes and promoting the expansion of beneficial microbes in CKD rats. Collectively, our findings demonstrated that Mahuang decoction mitigated kidney functional and structural impairment in CKD rats which were associated with the restoration of dysbiosis of intestinal microbiota, implying its potential in clinical CKD treatment.

Progress of carbon-based electrocatalysts for flexible zinc-air batteries in the past 5 years: recent strategies for design, synthesis and performance optimization.

The increasing popularity of wearable electronic devices has led to the rapid development of flexible energy conversion systems. Flexible rechargeable zinc-air batteries (ZABs) with high theoretical energy densities demonstrate significant potential as next-generation flexible energy devices that can be applied in wearable electronic products. The design of highly efficient and air-stable cathodes that can electrochemically catalyze both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are highly desirable but challenging. Flexible carbon-based catalysts for ORR/OER catalysis can be broadly categorized into two types: (i) self-supporting catalysts based on the in situ modification of flexible substrates; (ii) non-self-supporting catalysts based on surface coatings of flexible substrates. Methods used to optimize the catalytic performance include doping with atoms and regulation of the electronic structure and coordination environment. This review summarizes the most recently proposed strategies for the synthesis of designer carbon-based electrocatalysts and the optimization of their electrocatalytic performances in air electrodes. And we significantly focus on the analysis of the inherent active sites and their electrocatalytic mechanisms when applied as flexible ZABs catalysts. The findings of this review can assist in the design of more valuable carbon-based air electrodes and their corresponding flexible ZABs for application in wearable electronic devices.

Pseudocapacitance multiporous vanadyl phosphate/graphene thin film electrode for high performance electrochemical capacitors.

Supercapacitors are being considered as promising electricity storage devices with green sustainable energy conversion. To efficiently develop and optimize pseudocapacitive material of vanadyl phosphate, herein, multiporous vanadyl phosphate/graphene (denoted as MP-VOPO4@rGO) is fabricated for the first time with phytic acid as a phosphorus source by extremely simple sol-gel and drop coating methods, and used as the free binder thin film electrode of supercapacitors. The smart combination of honeycomb-like architecture and graphene incorporation results in more active sites and low internal resistance, significantly improving energy storage performance. The effect of introducting polystyrene (denoted as PS) template and rGO on the performance of the nanocomposite is systematically analyzed by comparing the performance of the corresponding thin film electrodes. The MP-VOPO4@rGO thin film electrode delivers superior pseudocapacitive performance of 672 F g-1 at 1 A g-1 as well as a remarkable rate capability of 552 F g-1 at 5 A g-1, and it presents a remarkable longterm cycling stability, with a capacitance retention of 83.5% after 5000 cycles. Very interestingly, the results of surface capacitance contribution dominance clearly demonstrates its rapid capacitive response. In addition, based on MP-VOPO4@rGO thin film as positive and negative electrodes, the corresponding assembled symmetric supercapacitors exihibits outstanding energy density of 26.3 Wh kg-1 at power density of 249.9 W kg-1. This investigation can not only provide a versatile strategy to design other thin film electrode materials but also open up a new insight into the development of polyanion phosphate composites for next-generation high performance energy storage systems.

Hierarchical NiMoO4@Co3V2O8 hybrid nanorod/nanosphere clusters as advanced electrodes for high-performance electrochemical energy storage.

Herein, a synergistic strategy to construct hierarchical NiMoO4@Co3V2O8 (denoted as NMO@CVO) hybrid nanorod/nanosphere clusters is proposed for the first time, where Co3V2O8 nanospheres (denoted as CVO) have been uniformly immobilized on the surface of the NiMoO4 nanorods (denoted as NMO) via a facile two-step hydrothermal method. Due to the surface recombination effect between NMO and CVO, the as-prepared NMO@CVO effectively avoids the aggregation of CVO nanosphere clusters. The unique hybrid architecture can make the most of the large interfacial area and abundant active sites for storing charge, which is greatly beneficial for the rapid diffusion of electrolyte ions and fast electron transport. The optimized NMO@CVO-8 composite nanostructure displays battery-like behavior with a maximum specific capacity of 357 C g-1, excellent rate capability (77.8% retention with the current density increasing by 10 times) and remarkable cycling stability. In addition, an aqueous asymmetric energy storage device is assembled based on the NMO@CVO-8 hybrid nanorod/nanosphere clusters and activated carbon. The device shows an ultrahigh energy density of 48.5 W h kg-1 at a power density of 839.1 W kg-1, good rate capability (20.9 W h kg-1 even at 7833.7 W kg-1) and excellent cycling stability (83.5% capacitance retention after 5000 cycles). More notably, two charged devices in series can light up a red light-emitting diode (LED) for 20 min, demonstrating its potential in future energy storage applications. This work indicates that the hierarchical NiMoO4@Co3V2O8-8 hybrid nanorod/nanosphere clusters are promising energy storage materials for future practical applications and also provides a rational strategy for fabricating novel nanostructured materials for high-performance energy storage.

Deregulation of long noncoding RNA (TUG1) contributes to excessive podocytes apoptosis by activating endoplasmic reticulum stress in the development of diabetic nephropathy.

The objective of this study was to investigate the molecular mechanism of how TUG1 interferes with the expression of C/EBP homologous protein (CHOP), peroxisome-proliferator-activated receptor-γ coactivator-1 alpha (PGC-1α), which contributes to the development of diabetic nephropathy. Real-time polymerase chain reaction and western blot analysis were performed to explore the regulatory relationship among TUG1, CHOP, PGC-1α, and caspase-3. Terminal deoxynucleotidyl transferase dUTP nick-end labeling was performed to confirm TUG1 involved in diabetic nephropathy (DN) through influencing podocytes apoptosis. TUG1 was highly expressed in a cell following treatment with high glucose, and PGC-1α and cleaved caspase-3 levels were much lower, while CHOP level was much higher in high glucose group (HG), furthermore, CHOP inhibited PGC-1α expression. TUG1 negatively regulated CHOP expression, and positively regulated PGC-1α expression. Meanwhile, total caspase-3 level in cell treated with or without HG transfected with CHOP small interfering ribonucleic acid (siRNA), TUG1, and TUG1 siRNA showed no evident difference with their corresponding control, while CHOP siRNA and TUG1 evidently decreased, and TUG1 siRNA remarkably increased cleaved caspase-3 level in HG or normal glucose groups in comparison with corresponding control. TUG1 and PGC-1α levels were much lower, while CHOP level was much higher in participants diagnosed with DN. A higher level of CHOP protein and lower level of PGC-1α were observed in subjects diagnosed with DN. Finally, podocytes apoptosis in the DN group was significantly promoted compared with that in nondiabetic renal disease group. Our current study has suggested for the first time that the long noncoding RNA (lncRNA) TUG1 influenced podocytes apoptosis via mediating endoplasmic reticulum stress (ERS)-CHOP-PGC-1α signaling pathway in HG-induced DN.