The development of a green system to solubilize cellulose from raw biomass is important, yet it is challenging because of the insolubility of cellulose in most solvents. Herein, a green NaCl-H2 O system is developed in which NaCl significantly enhances the dissolution and depolymerisation of cellulose from raw biomass. Nearly all the cellulose in the selected biomass types was dissolved and degraded into oligomers with molecular weights of 200-400 Da under relatively mild conditions. Cl(-) could interact strongly with the end OH group of the glucose unit in a 1:1 ratio, which resulted in the enhanced breaking of both inter- and intramolecular hydrogen bonds. In particular, the intermolecular hydrogen bond with an FTIR band at approximately v=3200 cm(-1) was disrupted significantly by Cl(-) . The FTIR band for a hydrogen bond between hemicellulose and lignin might appear at v=1636 cm(-1) , whereas this bond could be almost totally broken under hydrothermal conditions at 220 °C.

Iron, nitrogen‐codoped carbon (Fe−N−C) nanocomposites have emerged as viable electrocatalysts for the oxygen reduction reaction (ORR) due to the formation of FeNxCy coordination moieties. In this study, results from first‐principles calculations show a nearly linear correlation of the energy barriers of key reaction steps with the Fe magnetic moment. Experimentally, when single Cu sites are incorporated into Fe−N−C aerogels (denoted as NCAG/Fe−Cu), the Fe centers exhibit a reduced magnetic moment and markedly enhanced ORR activity within a wide pH range of 0–14. With the NCAG/Fe−Cu nanocomposites used as the cathode catalyst in a neutral/quasi‐solid aluminum–air and alkaline/quasi‐solid zinc–air battery, both achieve a remarkable performance with an ultrahigh open‐circuit voltage of 2.00 and 1.51 V, large power density of 130 and 186 mW cm−2, and good mechanical flexibility, all markedly better than those with commercial Pt/C or Pt/C‐RuO2 catalysts at the cathode.

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Hydrogel is used as a structural template and precursor to prepare carbon aerogel doped with Fe–Co bimetal sites as bifunctional catalysts for ORR and OER, which exhibits enhanced activity and stability, as compared to the monometal counterparts.