Nutrient-Doped Hydroxyapatite: Structure, Synthesis and Properties

Abstract

Complex inorganic powders based on calcium phosphates have found a plethora of practical applications. Of particular interest are the CaO-P2O5 system-based multi-component material powders and granules as the source of major- and micronutrients for the plants. The emerging strategy is to use nano fertilizers based on hydroxyapatite (HAP) for phosphorus and other nutrient delivery. The doping of micronutrients into HAP structure presents an interesting challenge in obtaining specific phase compositions of these calcium phosphates. Various techniques, including mechanochemical synthesis, have been employed to fabricate doped HAP. Mechanochemical synthesis is of particular interest in this review since it presents a relatively simple, scalable, and cost-effective method of calcium phosphate powder processing. The method involves the use of mechanical force to promote chemical reactions and create nanometric powders. This technique has been successfully applied to produce HAP nanoparticles alone, and HAP doped with other elements, such as zinc and magnesium. Nanofertilizers developed through mechanochemical synthesis can offer several advantages over conventional fertilizers. Their nanoscale size allows for rapid absorption and controlled release of nutrients, which leads to improved nutrient uptake efficiency by plants. Furthermore, the tailored properties of HAP-based nano fertilizers, such as controlled porosity and degradation levels, contribute to their effectiveness in providing plant nutrition.

Carbonate Hydroxyapatite - A Multifunctional Bioceramics with Non-Medical Applications

“…CHA also simultaneously adsorbs organic pollutants like glyphosate and radionuclides [191]. Nanofertilzers doped with bioorganic molecules and ions can perform better due to increased surface area, porosity, and easy degradability [192]. A surface coating for stonework made of CHA doped with zinc, strontium, and magnesium increased their mechanical strength and decreased water absorption, ultimately improving their surface durability [193].…”

Synthesis of nano-hydroxyapatite using emulsion, pyrolysis, combustion, and sonochemical methods and biogenic sources: a review

“…Bacteria, fungi, or plants are biological organisms that can be used as biogenic sources that function as templates or nucleation sites to synthesize nano-HAp, resulting in the generation of nanostructured particles. 43 Sonochemical methods induce acoustic cavitation in a liquid medium via high-intensity ultrasound, which leads to the development of nanostructured HAp particles, facilitated by the presence of localized heated regions and elevated pressure. 44…”

“…42 Bacteria, fungi, or plants are biological organisms that can be used as biogenic sources that function as templates or nucleation sites to synthesize nano-HAp, resulting in the generation of nanostructured particles. 43 Sonochemical methods induce acoustic cavitation in a liquid medium via high-intensity ultrasound, which leads to the development of nanostructured HAp particles, facilitated by the presence of localized heated regions and elevated pressure. 44 2 Methods of synthesis for HAp NPs Numerous methods are used to synthesize synthetic HAp: solid state, 24 mechanochemical, 25 chemical, 26 hydrolysis, 27 sol-gel, 28 pyrolysis, 29 combustion, 30 sonochemical, 31 and emulsion.…”

Acid-Free Processing of Phosphorite Ore Fines into Composite Fertilizers Using the Mechanochemical Activation Method

“…While growing crops for plant nutrition, phosphate fertilizers are of paramount importance. Phosphorus affects the development of the plant root system, which in turn performs the main function in providing nutrients necessary for plant growth and productivity [2][3][4][5].…”