Defect engineering is an effective way to modulate the electric states and provide active sites for electrocatalytic reactions. However, most studied oxygen vacancies are unstable and susceptible under the oxygen circumstance. Here, we fabricated cobalt-defected Co3–xO4 in situ for an efficient oxygen evolution reaction (OER). XAFS and PALS characterizations show that the crystals have abundant Co vacancies and a distorted structure. DFT calculations indicate that the metal defects lead to obvious electronic delocalization, which enhances the carrier transport to participate in water-splitting reactions along the defective conducting channels and the water adsorption/activation on the catalyst surface. Therefore, cobalt-defected Co3–xO4 shows remarkably high OER activity by delivering a much lower overpotential of 268 mV@10 mA cm–2 (with a small Tafel slope of 38.2 mV/dec) for OER in KOH electrolyte, in comparison with normal Co3O4 (376 mV), IrO2 (340 mV), and RuO2 (276 mV). This work opens up a promising approach to construct electronic delocalization structures in metal oxides for high-performance electrochemical catalysts.
A sacrificial template strategy is developed to synthesize highly dispersed γ-Fe2O3 embedded in porous N-doped carbon. The as-synthesized catalyst exhibits high ORR performance and presents a power density of 112 mW cm−2 in zinc–air battery.
Solar-driven interfacial water evaporation (SDIWE) endures a significant potential for producing clean water from seawater and wastewater because it requires no additional energy source. Photothermal materials with efficient solar absorption and pollutant removal capabilities are critical for SDIWE. However, an efficient and facile strategy to prepare a high-performance and flexible photothermal material and simultaneously prevent the salt accumulation for efficient and long-term steady evaporation to produce potable water from seawater and wastewater is still a challenge. Herein, a novel flexible photothermal material is synthesized using a flexible polyester textile substrate, hierarchical metal–organic framework Cu-BTC MOFs, and polypyrrole (PPy) as a light-absorption layer. In particular, under the synergistic effect of the hierarchical porous Cu-BTC MOFs and PPy with excellent solar absorption, the flexible photothermal material possesses excellent light absorption (above 92.58%), super hydrophilicity (contact angle is around 0° within 4.18 s), low thermal conductivity (~ 0.1131 W m-1 K-1), outstanding salt resistance, high evaporation rate (above 1.53 kg m-2 h-1) and photothermal conversion efficiency (89.16% under 1 sun) and excellent metal ions and organic pollutants removal capacity after solar evaporation. These multifunctional properties ensure its great application prospect for future freshwater production while also providing a new reference for other applications.
Cubic Iridium nanoparticles without any surfactants on the surface have been synthesized successfully in this work. The process of synthesis was quite simple by just injecting one drop of 400 µL solution containing Iridium precursor onto Cu foil (1 cm × 1 cm), and through galvanic reaction between the Ir precursor and Cu foil, the cubic Iridium nanoparticle could be obtained quite quickly (<30 s). The Cu foil played the roles of both reducing agent and substrate. This method could also be employed to synthesize cubic nanoparticles of other Pt-group metals such as Rh. By employing this method, cubic metal nanoparticles with surfactant-free surfaces could be produced economically and efficiently, and as a result, a realistic relationship between structure and catalytic activity could be established.
Abstract Research question Is deficiency of IL‐22 associated with premature ovarian insufficiency (POI)? Design Levels of IL‐22 and IL‐22BP, IL‐22‐producing T cells, and IL22RA1/IL10R2 expression were measured and compared among 29 patients with POI, 42 with precursor stage of POI (pre‐POI) and 46 control women. Correlation of serum IL‐22 and IL‐22 + CD4 + T subsets with ovarian reserve markers were further analyzed. Results IL‐22 levels in serum significantly differed among control women and patients with pre‐POI and POI, with the lowest concentrations in POI group ( p = .019). Significant reduction of peripheral CD4 + IL‐22 + T cells was observed in patients with POI ( p = .010), which mainly contributed by decrease of CD4 + IL‐22 + IL‐17 − T H 22 cells ( p = .012) but not T H 17 cells ( p = .125). Levels of serum IL‐22 and IL‐22‐producing CD4 + T subsets were significantly correlated with ovarian reserve markers, including AMH, bilateral AFC, follicle‐stimulating hormone (FSH), and E2 ( p < .05). The specific receptor IL22RA1 expression was marginally reduced in granulosa cells from patients with pre‐POI ( p = .051). No difference of IL‐22BP was observed either in serum ( p = .216) or follicular fluid ( p = .856) among groups. Conclusions Our study first demonstrated the significant association between T H 22‐mediated IL‐22 deficiency and ovarian insufficiency, which provide new insights into the autoimmune disturbance and opens new avenues for exogenous IL‐22 administration as potential intervention of POI.
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