Zn and Ni doped hydroxyapatite: Study of the influence of the type of energy source on the photocatalytic activity and antimicrobial properties

Abstract

The present work aimed to produce HAp nanoparticles doped with Zn and Ni in order to analyze the incorporation of these elements in the catalytic and antimicrobial properties of HAp. The samples were obtained by the microwave-assisted hydrothermal method in 30 min at 150 °C. XRD and FTIR results showed that HAp was formed without the presence of secondary phases, and Rietveld refinement indicated a reduction in crystallite size after doping. Nanorod-like morphologies were observed by SEM-FEG with reduction in particle size and increase in specific surface area. Furthermore, the hidden gap at 3.26 eV, photoluminescence indicated that there was a predominance of deep defects and XPS showed the presence of dopants on the HAp surface. The catalytic results in the degradation of methylene blue dye indicated that the zinc-doped sample removed 97.85 % under sunlight, 66.81 % under UV light and 70.64 % under ultrasound. After four cycles of reuse under sunlight, good photocatalytic performance was maintained, and inhibition tests indicated that holes and hydroxyls are the active radicals. Antimicrobial activity tests showed that zinc-doped and co-doped samples were efficient in inhibiting Gram-negative bacteria (Escherichia coli). This work brings a promising alternative application for hydroxyapatite in environmental and microbial remediation.