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)0.35Cl0.20(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.