Search

Metal‐free, strong‐base‐free, and solvent‐free synthesis of alkenyl heteroarenes through PhNO2/PhNH2 mediated direct olefination of methyl substituted N‐heteroarenes with benzylic alcohols was described. Detailed mechanistic studies indicated that in situ formed imine was the active intermediate for the olefination. PhNO2 protected benzylic alcohols from overoxidation, and PhNH2 not only acted as the coupling partner for the formation of intermediate imine, but also provides an alkaline condition for the generation of enamine salt. Gram scale reaction and the synthesis of three pharmaceutically relevant conjugated olefins were also successful using this methodology. [ABSTRACT FROM AUTHOR]

The commercially available 3,4,9,10‐perylenetetracarboxylic diimide (PTCDI) acted as a heterogeneous catalyst to catalyze aerobic oxidative synthesis of benzimidazoles, benzothiazoles, and quinoxalines from o‐substituted aniline derivatives and primary amines in high yields with oxygen as the terminal oxidant. The gram scale reaction and reusability (up to six cycles) of the PTCDI catalyst were also successful and would greatly benefit industrial applications. [ABSTRACT FROM AUTHOR]

An innovative photocatalytic fuel cell (PFC)-based self-powered system was developed by integrating the perovskite Ag3BiO3/Ti3C2 MXene plasmonic heterojunction with a self-breathing strategy, which was beneficial for developing high-performance self-powered photoelectrochemical biosensors. [ABSTRACT FROM AUTHOR]

The advancement of cost-effective, high-performance catalysts for both electrochemical oxygen reduction reactions (ORRs) and oxygen evolution reactions (OERs) is crucial for the widespread implementation of metal–air batteries. In this research, we fabricated leaf-like N-doped carbon frames embedded with Co nanoparticles by pyrolyzing a ZIF-L/carbon nanofiber (ZIF-L/CNF) composite. Consequently, the optimized ZIF-L/CNF-700 catalyst exhibit exceptional catalytic activities in both ORRs and OERs, comparable to the benchmark 20 wt% Pt/C and RuO2. Addressing the issue of diminished cycle performance in the Zn–air battery cycle process, further detailed investigations into the post-electrolytic composition reveal that both the carbon framework and Co nanoparticles undergo partial oxidation during both OERs and ORRs. Owing to the varying local pH on the catalyst surface due to the consumption and generation of OH− by OERs and ORRs, after OERs, the product is reduced-size Co particles, while after ORRs, the product is outer-layer Co(OH)2-enveloping Co particles. [ABSTRACT FROM AUTHOR]

A density functional theory method was employed to conduct theoretical calculations on the pyrolysis reaction pathways of lignin monomer model compounds with an aldehyde or carboxyl group under the catalytic effect of alkali metal ions Na+ and K+, exploring their influence on the formation of the small molecular gaseous products CO and CO2. The results indicate that Na+ and K+ can easily bind with the oxygen-containing functional groups of the lignin monomer model compounds to form stable and low-energy complexes. Except for benzaldehyde and p-hydroxybenzaldehyde, Na+ and K+ can facilitate the decarbonylation reactions of other benzaldehyde-based and phenylacetaldehyde-based lignin monomer model compounds during the pyrolysis process, thereby enhancing the generation of CO. When the characteristic functional groups on the benzene rings of benzaldehyde-based and phenylacetaldehyde-based lignin monomer model compounds are the same, the phenylacetaldehyde-based ones are more prone to undergo decarbonylation than the benzaldehyde-based ones. Additionally, both Na+ and K+ can inhibit the decarboxylation reactions of benzoic acid-based and phenylacetic acid-based lignin monomer model compounds, thereby restraining the formation of CO2. When the characteristic functional groups on the benzene rings of benzoic acid-based and phenylacetic acid-based lignin monomer model compounds are the same, the phenylacetic acid-based ones are more difficult to undergo decarboxylation than the benzoic acid-based ones. [ABSTRACT FROM AUTHOR]

Building a high-performance sensing platform is the key to developing sensitive sensors. Herein, a highly sensitive self-powered electrochemical sensor (SPES) was constructed using a WO3·H2O film as the cathode prepared by a hydrothermal method and Zn as the anode, and it could be applied to sensitive detection of microcystin (MC-RR). The WO3·H2O film with a larger specific surface area could boost the oxygen reduction reaction (ORR), which could achieve signal amplification and significantly increase the sensitivity of the sensors. Under the optimal conditions, there was a good linear relationship between the increased electrical power density and the logarithm of MC-RR concentration with a detection limit of 1.31 × 10−15 M (S/N = 3). This method had good anti-interference ability and stability when applied to the determination of MC-RR content in actual samples, which could boost the potential application of electrochemical sensors in the field of environmental monitoring. [ABSTRACT FROM AUTHOR]