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Abstract Development of high‐performance, low‐cost catalysts for electrochemical water splitting is key to sustainable hydrogen production. Herein, ultrafast synthesis of carbon‐supported ruthenium–copper (RuCu/C) nanocomposites is reported by magnetic induction heating, where the rapid Joule's heating of RuCl₃and CuCl₂at 200 A for 10 s produces Ru–Cl residues‐decorated Ru nanocrystals dispersed on a CuCl_xscaffold, featuring effective Ru to Cu charge transfer. Among the series, the RuCu/C‐3 sample exhibits the best activity in 1 mKOH toward both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), with an overpotential of only −23 and +270 mV to reach 10 mA cm⁻², respectively. When RuCu/C‐3 is used as bifunctional catalysts for electrochemical water splitting, a low cell voltage of 1.53 V is needed to produce 10 mA cm⁻², markedly better than that with a mixture of commercial Pt/C+RuO₂(1.59 V). In situ X‐ray absorption spectroscopy measurements show that the bifunctional activity is due to reduction of the Ru–Cl residues at low electrode potentials that enriches metallic Ru and oxidation at high electrode potentials that facilitates the formation of amorphous RuO_x. These findings highlight the unique potential of MIH in the ultrafast synthesis of high‐performance catalysts for electrochemical water splitting. 

Synergetic interactions between ruthenium and molybdenum oxide weaken H adsorption on ruthenium active sites and hence enhance the electrocatalytic activity towards hydrogen evolution reaction. 

Abstract Antibiotic‐resistant bacterial strains are an ever‐present hurdle for human health. A route to overcoming this threat is the development of effective antimicrobial agents based on carbon‐supported nanocomposites. In this study, carbon dots (CD) are synthesized by a facile hydrothermal treatment of ethylenediaminetetraacetic acid and melamine and further functionalized with nickel hydroxide colloids. Whereas CD alone exhibits virtually no antimicrobial activity under photoirradiation at 365 nm againstEscherichia coliin comparison to the blank control, the performance is markedly enhanced with the Ni(OH)₂‐CD nanocomposites, with the lag time prolonged from 7 to 15 h and growth rate reduced by ca. 15%. This is ascribed to the Ni(OH)₂colloids that facilitate the separation of photogenerated electron‐hole pairs and ensuing production of superoxide radicals, as confirmed by photoluminescence and electron paramagnetic resonance measurements, which induce oxidative stress and damage to the bacterial cell membranes, thereby leading to effective bactericidal activity. Consistent results are obtained in live/dead assays. Results from this work highlight the unique potential of carbon‐based composites in the development of next‐generation antimicrobial agents.