The development of highly active and durable catalysts for electrochemical reduction of CO2 (ERC) to CH4 in aqueous media is an efficient and environmentally friendly solution to address global problems in energy and sustainability. In this work, an electrocatalyst consisting of single Zn atoms supported on microporous N-doped carbon was designed to enable multielectron transfer for catalyzing ERC to CH4 in 1 M KHCO3 solution. This catalyst exhibits a high Faradaic efficiency (FE) of 85%, a partial current density of −31.8 mA cm–2 at a potential of −1.8 V versus saturated calomel electrode, and remarkable stability, with neither an obvious current drop nor large FE fluctuation observed during 35 h of ERC, indicating a far superior performance than that of dominant Cu-based catalysts for ERC to CH4. Theoretical calculations reveal that single Zn atoms largely block CO generation and instead facilitate the production of CH4.

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To avoid a spontaneous reaction between ZnO gas sensing materials and detected H2S gas, ZnO nanorods decorated with a several nm ZnS thin layer were designed. The ZnS-decorated layer was prepared by passivating oriented ZnO nanorods in a H2S atmosphere. The effect of the passivation processes on the H2S sensing properties was investigated. It was found that ZnO nanorods decorated with a 2 nm-thick ZnS layer possessed a repeatable and superior response to ppm-level H2S at room temperature. Moreover, a confinement effect was proposed to explain the improved sensing properties of the decorated ZnO nanorods.

N‐coordinated transition‐metal materials are crucial alternatives to design cost‐effective, efficient, and highly durable catalysts for electrocatalytic oxygen reduction reaction. Herein, the synthesis of uniformly distributed Cu−Zn clusters on porous N‐doped carbon, which are accompanied by Cu/Zn‐Nx single sites, is demonstrated. X‐ray absorption fine structure tests reveal the co‐existence of M−N (M = Cu or Zn) and M−M bonds in the catalyst. The catalyst shows excellent oxygen reduction reaction (ORR) performance in an alkaline medium with a positive half‐wave potential of 0.884 V, a superior kinetic current density of 36.42 mA cm−2 at 0.85 V, and a Tafel slope of 45 mV dec−1, all of which are among the best‐reported results. Furthermore, when employed as an air cathode in Zn‐Air battery, it reveals a high open‐cycle potential of 1.444 V and a peak power density of 164.3 mW cm−2. Comprehensive experiments and theoretical calculations approved that the high activity of the catalyst can be attributed to the collaboration of the Cu/Zn‐N4 sites with CuZn moieties on N‐doped carbons.

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