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The role of fungi in the biogeochemical cycling of gold remains unclear. Here the authors show that fungi can initiate gold oxidation under supergene conditions, thereby impacting gold mobilisation and secondary deposit formation in terrestrial environments.

Summary: Rechargeable Zn-ion batteries working with manganese oxide cathodes and mild aqueous electrolytes suffer from notorious cathode dissolution during galvanostatic cycling. Herein, for the first time we demonstrate the dynamic self-recovery chemistry of manganese compound during charge/discharge processes, which strongly determines the battery performance. A cobalt-modified δ-MnO2 with a redox-active surface shows superior self-recovery capability as a cathode. The cobalt-containing species in the cathode enable efficient self-recovery by continuously catalyzing the electrochemical deposition of active Mn compound, which is confirmed by characterizations of both practical coin-type batteries and a new-design electrolyzer system. Under optimized condition, a high specific capacity over 500 mAh g−1 is achieved, together with a decent cycling performance with a retention rate of 63% over 5,000 cycles. With this cobalt-facilitated deposition effect, the battery with low concentration (0.02 M) of additive Mn2+ in the electrolyte (only 12 atom % to the overall Mn) maintains decent capacity retention. : Catalysis; Electrochemical Energy Storage; Electrochemical Materials Science Subject Areas: Catalysis, Electrochemical Energy Storage, Electrochemical Materials Science

Abstract Iron single atom catalysts (Fe SACs) are the best‐known nonprecious metal (NPM) catalysts for the oxygen reduction reaction (ORR) of polymer electrolyte membrane fuel cells (PEMFCs), but their practical application has been constrained by the low Fe SACs loading (