Hexagonal Mg(OH)₂ Nanosheets as Antibacterial Agent for Treating Contaminated Water Sources

Many water sources are contaminated by Gram-positive and Gram-negative pathogenic bacteria. In this work, low-cost antibacterial mesoporous nano-hexagonal Mg(OH)₂ sheets (MNMSs) with uniform sizes of 250–450 nm were fabricated. Their structural features enabled the sheets to be a powerful antibacterial agent with high surface reactivity owing to well-scattered pore windows that provide the sheets with a large surface area. Results revealed that the minimum inhibitory concentrations for Staphylococcus aureus and Escherichia coli bacteria were 0.45 and 0.50 mg ml⁻¹, respectively. MNMSs inhibited >97% of very high viable bacterial count 90×10⁴ cfu ml⁻¹ in a one-step process through 12 hours. Complete inhibition of bacterial growth occurred while maintaining the MNMSs layer composition, indicating reusability. The MNMSs antibacterial agent surface areas were 21.83 and 20.09 m² g⁻¹ for before and after usage, respectively, while the pore volume has no significant differences for MNMSs before and after usage represented by 0.043 and 0.044 cm³ g⁻¹, respectively. The treated bacterial cells were completely inactivated through the interaction of nanosheets with bacteria, leading to extensively damaged cell membranes and decomposition of internal cellular components. Therefore, the MNMSs can be used to treat biological pollution in water.