(NH₄)Fe₂(PO₄)₂(OH)·2H₂O samples with different morphology are successfully synthesized via two-step synthesis route - ultrasonic-intensified impinging stream pre-treatment followed by hydrothermal treatment (UIHT) method. The effects of the adoption of ultrasonic-intensified impinging stream pre-treatment, reagent concentration (C), pH value of solution and hydrothermal reaction time (T) on the physical and chemical properties of the synthesised (NH₄)Fe₂(PO₄)₂(OH)·2H₂O composites and FePO₄ particles were systematically investigated. Nano- seeds were firstly synthesized using the ultrasonic-intensified T-mixer and these nano-seeds were then transferred into a hydrothermal reactor, heated at 170 °C for 4 hours. The obtained samples were characterized by utilising XRD, BET, TG-DTA, SEM, TEM, Mastersizer 3000 and FTIR, respectively. The experimental results have indicated that the particle size and morphology of the obtained samples are remarkably affected by the use of ultrasonic-intensified impinging stream pre-treatment, hydrothermal reaction time, reagent concentration, and pH value of solution. When such (NH₄)Fe₂(PO₄)₂(OH)·2H₂O precursor samples were transformed to FePO₄ products after sintering at 650°C for 10 hours, the SEM images have clearly shown that both the precursor and the final product still retain their monodispersed spherical microstructures with similar particle size of about 3 μm when the samples are synthesised at the optimised condition.

通过两步法合成了不同形态的（NH ₄）Fe ₂（PO ₄）₂（OH）·2H ₂ O样品-超声强化撞击流预处理，然后进行水热处理（UIHT）。超声强化撞击流预处理，试剂浓度（C），溶液pH值和水热反应时间（T）对合成的（NH ₄）Fe ₂（PO ₄）的理化性能的影响）₂（OH）·2H ₂ O复合材料和FePO ₄系统地研究了颗粒。首先使用超声强化T混合器合成纳米种子，然后将这些纳米种子转移到水热反应器中，在170°C下加热4小时。分别利用XRD，BET，TG-DTA，SEM，TEM，Mastersizer 3000和FTIR对所得样品进行表征。实验结果表明，超声强化撞击流预处理，水热反应时间，试剂浓度和溶液pH值对所得样品的粒径和形貌有显着影响。当将这样的（NH ₄）Fe ₂（PO ₄）₂（OH）·2H ₂ O前体样品转化为FePO _4时 产品在650°C烧结10小时后，SEM图像清楚地表明，当在最佳条件下合成样品时，前体和最终产品仍保留着粒径约为3μm的单分散球形微结构。