Macroporous Ag/HA materials for antibacterial photothermal membranes in solar steam generation systems

The increasing global demand for clean water has driven significant research into solar steam generation and water purification technologies. Hydroxyapatite (HA), a biocompatible and chemically stable material, has demonstrated promise for water treatment due to its excellent adsorption properties. However, microbial contamination poses a significant challenge to its application for solar steam generation. Herein, a novel macroporous silver-doped hydroxyapatite (Ag/HA) nanocomposite was used for the first time in fabricating photothermal membranes. The incorporation of 8.8% atomic percentage Ag into Ag/HA significantly alters its structure, introducing macroporous voids, which are excellent for water transportation and steam release in solar steam generation. The results show that the Ag/HA membrane achieved an evaporation rate of 1.202 kgm⁻² h⁻¹ under one-sun illumination, a 1.33-fold increase compared to pure HA membranes. Additionally, antibacterial evaluations using the disk diffusion method revealed significant antibacterial activity against Escherichia coli and Staphylococcus aureus, with inhibition zones increasing with Ag/HA concentration. These findings highlight the potential of Ag/HA nanocomposites as an efficient and durable solution for water harvesting and purification.