Calcium phosphate powder synthesis by out-of-phase pulsed sonoelectrochemistry

•Out of phase pulsed sonoelectrodeposition calcium phosphate nanoparticles synthesis.•pH modification near ultrasonic horn (working electrode) generates calcium phosphate precipitation.•High aspect ratios calcium-deficient hydroxyapatite nanorods can be produced.•Change in the electrolyte pH modifies the calcium phosphate nanoparticles compositions and phases. High aspect ratio calcium phosphate (CaP) nanorods were achieved by out-of-phase pulsed sonoelectrodeposition from electrolytic aqueous bath composed of calcium nitrate, ammonium dihydrogenophosphate and surfactant at pH of 4.9. The nature of CaP phases was determined by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR) and energy dispersive X-ray spectroscopy (EDX). The results reveal the predominantly presence of calcium deficient hydroxyapatite (CDHA). The transmission electron microscopy (TEM) analyzes highlighted that the nanorods are polycristalline and have an aspect ratio up to 30.