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Arnicolide B and arnicolide C are two sesquiterpene lactones isolated and identified from Centipeda minima, but the anti-inflammatory effects and mechanisms of these two compounds have not been reported. In this study, LPS was used to establish RAW 264.7 macrophages inflammatory response model. Griess, ELISA, Western blot were used to investigate the anti-inflammatory effects in vitro and the molecular mechanisms of these two active compounds. The results showed that arnicolide B and arnicolide C could not only inhibit the production of inflammatory mediators NO, PGE2, TNF-α and IL-6, but also down-regulate the high expression of inflammatory proteins iNOS and COX-2. Furthermore, arnicolide B and arnicolide C inhibited the phosphorylation of ERK, JNK, p38 proteins in the MAPK signaling pathway, but had no effect on the degradation of IκB-α protein and the activation of the NF-κB pathway. As conclusion, these two compounds exert anti-inflammatory effects by inactivation of the MAPK pathway. [ABSTRACT FROM AUTHOR]

Hybrid lead halides show significant potential in photocatalysis due to their excellent photophysical properties, but the atomically precise modification of their organic component to achieve synergistic interactions with the lead halide units remains a great challenge. Herein, for the first time, we have employed the crystal engineering strategy to construct a class of single‐atom‐substituted hybrid lead halides with electron donor‐acceptor (D‐A) effect. The lead halide frameworks consist of 1D linear [PbCl]+ chains as inorganic building units and benzoxadiazole/benzothiadiazole/ benzoselenadiazole‐funtionalized dicarboxylates as linkers. The covalent bonding between the organic ligands with electron−withdrawing groups and the electron‐rich lead halide units not only facilitate the charge separation, but also enhance structural robustness that is critical for photocatalysis. The D‐A structured lead halides serve as highly efficient heterogeneous photooxidation catalysts, including aerobic oxidation of C(sp3)−H bonds, oxidative coupling of primary amines, oxidation of phenylboronic acids and selective oxidation of sulfides that are demonstrated in 30 examples. Importantly, these photooxidation reactions are able to be driven by natural sunlight and ambient air to afford quantitative yields. Moreover, our lead halide photocatalysts are successful to fix into a photocatalytic flow system, which enables the flow‐type synthesis of high value‐added photooxidation products on a gram scale. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide produced by electrochemical oxygen reduction reaction provides a potentially cost effective and energy efficient alternative to the industrial anthraquinone process. In this study, we demonstrate that by modulating the oxygen functional groups near the atomically dispersed cobalt sites with proper electrochemical/chemical treatments, a highly active and selective oxygen reduction process for hydrogen peroxide production can be obtained in acidic electrolyte, showing a negligible amount of onset overpotential and nearly 100% selectivity within a wide range of applied potentials. Combined spectroscopic results reveal that the exceptionally enhanced performance of hydrogen peroxide generation originates from the presence of epoxy groups near the Co–N4 centers, which has resulted in the modification of the electronic structure of the cobalt atoms. Computational modeling demonstrates these electronically modified cobalt atoms will enhance the hydrogen peroxide productivity during oxygen reduction reaction in acid, providing insights into the design of electroactive materials for effective peroxide production. The production of hydrogen peroxide by electrochemical oxygen reduction is an attractive alternative to the industrial process, but catalysts should be optimized. Here, the authors enhance hydrogen peroxide production in acidic media with epoxy groups near cobalt centers on carbon nanotubes. [ABSTRACT FROM AUTHOR]

Renewable electricity powered water electrolysis is a promising solution for the conversion and storage of the intermittent renewable energy resources in the form of hydrogen. Herein, atomically thin FeCoNi ternary (oxy)hydroxide nanosheets (FeCoNi‐ATNs) are developed as efficient and robust bifunctional electrocatalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in 1 m KOH solution (pH = 14). The electrocatalyst shows remarkably high apparent catalytic performance (400 mA cm−2 at 350 mV for OER and 240 mV for HER) and mass activities at modest overpotentials (1931 A g−1 at 330 mV for OER; 1819 A g−1 at 200 mV for HER). Moreover, the OER and HER performance of FeCoNi–ATNs are fully reversible and electrochemically switchable, due to the interconversion attribute of two catalytic states for OER and HER. Using the dual functional properties of this catalyst, a fully reversible water electrolyzer cell is fabricated, exhibiting a robust reversibility between two half reactions in water electrolysis under a high current density (100 mA cm−1), which can effectively overcome the stability issues caused by electrode depolarization during frequent power interruptions, an inevitable phenomenon commonly brought about by the usage of intermittent renewable energy supplies. [ABSTRACT FROM AUTHOR]

The development of highly active and cost‐effective catalyst materials toward electrochemical water splitting is of great importance for converting and storing the intermittent solar energy in the form of hydrogen. Herein, for the first time, an ultrathin Fe and N‐co‐doped carbon nanosheet encapsulated Fe‐doped CoNi alloy nanoparticle (FeCoNi@FeNC) composite is obtained and applied as a bifunctional catalyst for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). This catalyst exhibits prominent catalytic performances for both HER and OER, which only requires overpotentials of 102 and 330 mV, respectively, to reach a current density of 10 mA cm−2 in alkaline media. The high catalytic activity is intrinsically associated with the presence of Fe in both nanosheets and nanoparticles, which has triggered the occurrence of coordinative effects between Fe‐N‐C and FeCoNi that are beneficial for HER and OER, as revealed by electrochemical techniques. In an overall water splitting electrolyzer, FeCoNi@FeNC is employed as both the cathode and anode catalysts, achieving 12 mA cm−2 at 1.63 V for a duration of more than 12 h. Fe and N co‐doped carbon nanosheet encapsulated Fe‐doped CoNi nanoparticles are successfully synthesized and served as efficient precious‐metal‐free bifunctional electrocatalysts for hydrogen evolution reaction and oxygen evolution reaction in alkaline with excellent catalytic performances. The two‐electrode electrolyzer using FeCoNi@FeNC composite as both cathode and anode catalysts exhibits a current density of 12 mA cm−2 at a potential of 1.63 V. [ABSTRACT FROM AUTHOR]

Active and cost‐effective catalyst materials are required for electrochemical CO2 reduction reactions (CO2RR) which, to date, are proving elusive. Here, the direct electrochemical conversion of CO2 to liquid products with a high overall Faradaic efficiency (FE) by utilizing a unique 3D, heterostructured copper electrode (referred as Cu sandwich) that is obtained via a simple two‐step treatment of commercially available copper foam is reported. The designed catalyst achieves an FE toward liquid products of >50% at an applied potential as low as −0.3 V versus reversible hydrogen electrode. The improved selectivity of the heterostructured Cu sandwich electrode at low overpotentials is attributed to the greater exposure of engineered Cu+/Cu2+ interfaces (present on composite nanowires) and higher oxygen vacancy defects. Moreover, the rationally designed heterostructures prevent the Cu2O species from being reduced during CO2RR enabling the catalyst to demonstrate enhanced CO2RR activity with prolonged stability. A 3D heterostructured copper electrode (Cu sandwich) for CO2 reduction reactions (CO2RR) is fabricated by a simple two‐step treatment of commercially available copper foam. The catalyst demonstrates a high selectivity toward ethanol and methanol production during CO2RR. The improved selectivity of the Cu sandwich can be explained by the presence of Cu+/Cu2+ interfaces and oxygen vacancy defects. [ABSTRACT FROM AUTHOR]

Electrochemical oxidation of glycerol into value-added chemicals represents a sustainable approach for not only valorizing biomass resources but also improving the energy efficiency of electrolysis by replacing the kinetically sluggish oxidation of water at the anode. Here, we present a nickel (oxy)hydroxide supported cobalt nanoneedle arrays catalyst (CoNA-NiOH/NF-2) for effective oxidation of glycerol. The loaded Co(OH) 2 forms more oxygen defects, increases the active sites, and enhances the performance of glycerol oxidation. The CoNA-NiOH/NF-2 catalyst significantly reduces energy consumption by achieving a current density of 10 mA cm -2 at a low voltage of 1.22 V vs. RHE, and 100 mA cm -2 at 1.42 V vs. RHE, which is approximately 240 mV lower than oxygen evolution reaction (OER). Additionally, the Faraday efficiency of formate generation reached 98 %. The growth of renewable energy sources will greatly benefit from this strategy, which calls for replacing anodic OER with biomass oxidation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The electrochemical oxygen reduction reaction (ORR) provides a green route for decentralized H 2 O 2 synthesis, where a structure-selectivity relationship is pivotal for the control of a highly selective and active two-electron pathway. Here, we report the fabrication of a boron and nitrogen co-doped turbostratic carbon catalyst with tunable B-N-C configurations (CNB-ZIL) by the assistance of a zwitterionic liquid (ZIL) for electrochemical hydrogen peroxide production. Combined spectroscopic analysis reveals a fine tailored B-N moiety in CNB-ZIL, where interfacial B-N species in a homogeneous distribution tend to segregate into hexagonal boron nitride domains at higher pyrolysis temperatures. Based on the experimental observations, a correlation between the interfacial B-N moieties and HO 2 - selectivity is established. The CNB-ZIL electrocatalysts with optimal interfacial B-N moieties exhibit a high HO 2 - selectivity with small overpotentials in alkaline media, giving a HO 2 - yield of ≈1787 mmol g catalyst -1  h -1 at -1.4 V in a flow-cell reactor., (© 2022 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

In this study, we propose a top-down approach for the controlled preparation of undercoordinated Ni-N x (Ni-hG) and Fe-N x (Fe-hG) catalysts within a holey graphene framework, for the electrochemical CO 2 reduction reaction (CO 2 RR) to synthesis gas (syngas). Through the heat treatment of commercial-grade nitrogen-doped graphene, we prepared a defective holey graphene, which was then used as a platform to incorporate undercoordinated single atoms via carbon defect restoration, confirmed by a range of characterization techniques. We reveal that these Ni-hG and Fe-hG catalysts can be combined in any proportion to produce a desired syngas ratio (1-10) across a wide potential range (-0.6 to -1.1 V vs RHE), required commercially for the Fischer-Tropsch (F-T) synthesis of liquid fuels and chemicals. These findings are in agreement with our density functional theory calculations, which reveal that CO selectivity increases with a reduction in N coordination with Ni, while unsaturated Fe-N x sites favor the hydrogen evolution reaction (HER). The potential of these catalysts for scale up is further demonstrated by the unchanged selectivity at elevated temperature and stability in a high-throughput gas diffusion electrolyzer, displaying a high-mass-normalized activity of 275 mA mg -1 at a cell voltage of 2.5 V. Our results provide valuable insights into the implementation of a simple top-down approach for fabricating active undercoordinated single atom catalysts for decarbonized syngas generation.

Inspired by natural photosynthesis, the Z-scheme photocatalyst is a promising approach to extend the absorption spectra of photocatalysts and reduce the recombination of photo-generated electrons and holes. However, the fabrication of well-structured efficient multi-component Z-scheme photocatalysts is still a big challenge. We report here a facile one-pot method to synthesize graphene-based Z-scheme photocatalysts. The one-pot method guarantees good distribution of well-structured individual components on thin-layered rGO sheets with excellent connections. With inactive WO3 nanorods and inactive β-In2S3 nanosheets attached to the surface of the rGO sheets, the synthesized In2S3/WO3/rGO tertiary nanocomposite shows excellent visible-light catalytic activity for hydrogen production at 1524 μmol g(-1) h(-1), demonstrating unambiguously the Z-scheme catalytic mechanism. To prevent cross-reactions and interferences, our strategy was to choose no more than one ionic precipitation reaction for the one-pot process, as unwanted cross-reactions could become inevitable if many cations and anions were present. This fabrication strategy should be applicable generally to synthesize other multiple-component nanocomposites, as demonstrated also by the preliminary results of the successful synthesis of the BiVO4/WO3/rGO nanocomposite (one ionic precipitation reaction and one hydrolysis reaction) and WO3/TiO2/rGO nanocomposite (two hydrolysis reactions).