Hybrid system of nickel–cobalt hydroxide on carbonised natural cellulose materials for supercapacitors

Intrinsic Oxidase-like Nanoenzyme Co4S3/Co(OH)2 Hybrid Nanotubes with Broad-Spectrum Antibacterial Activity

Improving the antibacterial activity of nanomaterials and avoiding the use of H₂O₂ are vital for biosecurity and public health. In this work, novel Co₄S₃/Co(OH)₂ hybrid nanotubes (HNTs) for the first time were successfully synthesized through the control of Na₂S treatment of Co(CO₃)_0.35Cl_0.20(OH)_1.10 precursor. On the basis of Kirkendall effect, acicular precursor was vulcanized to form Co₄S₃/Co(OH)₂ HNTs that possess great properties including favorable storage ability and ideal stability. By tailoring the composition and structure, Co₄S₃/Co(OH)₂ HNTs were found to have profound oxidase-like catalytic activities. When pH = 3 precursor was treated with 900 mg of Na₂S, Co₄S₃/Co(OH)₂ HNTs exhibit superior performance. Owing to the outstanding oxidase-like activity, Co₄S₃/Co(OH)₂ HNTs can eliminate Escherichia coli, Pseudomonas aeruginosa, Staphylococcus sciuri, and Bacillus without the help of H₂O₂. It turned out that the sterilization ability came from the superoxide anion radical generated by Co₄S₃/Co(OH)₂ HNTs. With Co₄S₃/Co(OH)₂ HNTs, the intracellular reactive oxygen species level can be enhanced and the toxicity of H₂O₂ can be absolutely avoided. Overall, the synthesis of antibacterial nanomaterials is unparalleled and the results of this work would facilitate the utilization in medical science, new energy, and environmental catalysis.