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The dissolution of active material in aqueous batteries can lead to a rapid deterioration in capacity, and the presence of free water can also accelerate the dissolution and trigger some side reactions that affect the service life of aqueous batteries. In this study, a MnWO4 cathode electrolyte interphase (CEI) layer is constructed on a δ-MnO2 cathode by cyclic voltammetry, which is effective in inhibiting the dissolution of Mn and improving the reaction kinetics. As a result, the CEI layer enables the δ-MnO2 cathode to produce a better cycling performance, with the capacity maintained at 98.2% (vs. activated capacity at 500 cycles) after 2000 cycles at 10 A g−1. In comparison, the capacity retention rate is merely 33.4% for pristine samples in the same state, indicating that this MnWO4 CEI layer constructed by using a simple and general electrochemical method can promote the development of MnO2 cathodes for aqueous zinc ion batteries. [ABSTRACT FROM AUTHOR]

Meerwein-Ponndorf-Verley (MPV) reduction has gained much attention due to is mid reaction conditions, and this reaction can be performed without the presence of reductive atmosphere and the reaction conditions of high temperature and high pressure. Solid bases with abundant strong basic sites can be synthesized with metal-organic frameworks (MOFs) as precursors. These MOFs are immobilized with alkane metal nitrides, followed by calcination to produce the desired basic metal oxides. The basic zirconia shows highly efficient catalytic performance in MPV reduction of substrates with the carbonyl group, and benzaldehyde can be completely reduced in 6 hours with a mild reaction temperature (160 °C) in the absence of hydrogen gas. The catalytic efficiency is determined by the amounts of strong basic sites, but not the total amounts of basic sites, and this phenomenon is proved by the contrast experiments with the catalytic test of weak solid bases. Furthermore, the cooperative action between basic and acid sites can also enhance the catalytic performance in MPV reactions. With MOFs as precursors, metal oxide catalysts can be synthesized with well dispersed active sites. [ABSTRACT FROM AUTHOR]

Herein, we have developed a sequential visible-light-promoted Wolff rearrangement of 1-diazonaphthalen-2(1 H )-ones, followed by capturing the in situ generated ketene intermediates with various alcohols, producing diverse 1 H -indene-3-carboxylates in moderate to good yields under mild reaction conditions. The broad substrate scope, high functional group tolerance, and robust conditions make the resulting derivative a versatile platform for the synthesis of plenty of bioactive molecules.

The MnO 2 cathode has attracted extensive attention in aqueous zinc ion battery research due to its environmental benignity, low cost, and high capacity. However, sluggish kinetics of hydrated zinc ion and manganese dissolution lead to insufficient rate and cycle performances. In this study, a manganese phosphate nanolayer synthesized in situ on a MnO 2 cathode can be transformed into a δ-MnO 2 nanolayer interphase after activation upon cycling, endowing the interphase with abundant interlayer water. As a result, the δ-MnO 2 nanolayer interphase with the function of H + topochemistry significantly enhances H + (de)insertion in the MnO 2 cathode, which leads to a kinetics conversion from Zn 2+ -dominated (de)insertion to H + -dominated (de)insertion, thus endowing the MnO 2 cathode with superior rate and cycle performances (85.9% capacity retention after 1000 cycles at 10 A g -1 ). This strategy can be highly scalable for other manganese-based cathodes and provides an insight for developing high-performance aqueous zinc ion batteries.

H + intercalation, as a critical battery chemistry, enables electrodes' high rate performance due to the fast diffusion kinetics of H + . In this work, more water molecules are introduced into δ-MnO 2 by the protonation of δ-MnO 2 with abundant oxygen vacancies. Benefiting from the structure with a close arrangement of water molecules in interlayers, the Grotthuss transport of proton is achieved in the energy storage of the δ-MnO 2 cathode. As a result, the δ-MnO 2 cathode exhibits an ultrahigh rate performance with a capacity of 368.1 mAh g -1 at 0.5 A g -1 and 83.4 mAh g -1 at 50 A g -1 , which has a capacity retention of 73% after 1100 cycles at 10 A g -1 . The study of the storage mechanism reveals that the Grotthuss intercalation of proton predominates the storage process, which empowers the cathode with high rate performance.