Search

SrFe 1- x Si x O 3-δ F y cathode materials ( x = 0.05, 0.1, 0.15; y = 0, 0.1, 0.5) were prepared via a solid-state method. X-ray diffraction results show that the synthesized F doping samples were perovskite structure. X-ray photoelectron spectroscopy findings show that F - anions were doped into SrFe 1- x Si x O 3-δ . Transmission electron microscopy and energy-dispersive spectroscopy were performed to analyze the microstructure and element distribution in the materials, respectively. Double-layer composite cathode symmetric cells were prepared through a screen printing method. Scanning electron microscopy images revealed that the double-layer composite cathode adhered well to the electrolyte. The doping with F - can increase the coefficient of thermal expansion of SrFe 1- x Si x O 3-δ . The electrochemical impedance spectroscopy results indicate that the oxygen transport capacity of the SrFe 0.95 Si 0.05 O 3-δ material can be improved by doping with F - , but such a method can decrease the oxygen transport capacity of SrFe 0.9 Si 0.1 O 3-δ . At 800 °C, the peak power density of the single cell supported by an anode and SrFe 0.9 Si 0.1 O 3-δ F 0.1 as the cathode reached 388.91 mW/cm 2 . Thus, the incorporation of F - into SrFe 1- x Si x O 3-δ cathode materials can improve their electrochemical performance and enable their application as cathode materials for solid-oxide fuel cells., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Polychlorinated dibenzo-p-dioxins (PCDDs), as a group of notorious anthropogenic environmental toxicants, are arguably ubiquitous in nature. In this study, we investigated the photocatalytic reductive dechlorination of 2-chlorodibenzo-p-dioxin (2-CDD) over Pd/g-C 3 N 4 catalysts under UV-vis irradiation. The g-C 3 N 4 and a series of Pd/g-C 3 N 4 catalysts were prepared by thermal polymerization and mechanical mixing-illumination method and characterized by XRD, TEM, BET, SEM and UV-vis DRS analyses. Among all the samples, the Pd/g-C 3 N 4 (5 wt%) yielded the optimal dechlorination activity with a total 2-CDD conversion of 54% within 4 h, and 76% of those converted 2-CDD were evolved to dibenzo-p-dioxin (DD). The kinetics of dechlorination could be described as pseudo-first-order decay model (R 2  > 0.84). Corresponding rate constants (k) increased from 0.052 to 0.17 h -1 with Pd contents up to 5 wt% and decreased to 0.13 h -1 with a 10 wt% of Pd. The enhanced activities originated from the surface plasmonic resonance (SPR) effect of Pd nanoparticles and the formation of Schottky barrier between Pd and g-C 3 N 4 , which extend the spectrum responsive range and suppress the charge recombination of g-C 3 N 4 . This is the first report on the photocatalytic reductive removal of PCDDs and may provide a new approach for PCDDs pollution control., (Copyright © 2018 Elsevier B.V. All rights reserved.)