TY - JOUR AU - Allender, Christopher J. AU - Bowen, Jenna L. AU - Celorrio, Veronica AU - Davies-Jones, Josh A. AU - Davies, Philip R. AU - Guan, Shaoliang AU - O’Reilly, Padraic AU - Sankar, Meenakshisundaram PY - 2020 DA - 2020/08/06 TI - The Role of Growth Directors in Controlling the Morphology of Hematite Nanorods JO - Nanoscale Research Letters SP - 161 VL - 15 IS - 1 AB - The control of the growth of hematite nanoparticles from iron chloride solutions under hydrothermal conditions in the presence of two different structure promoters has been studied using a range of both structural and spectroscopic techniques including the first report of photo induced force microscopy (PiFM) to map the topographic distribution of the structure-directing agents on the developing nanoparticles. We show that the shape of the nanoparticles can be controlled using the concentration of phosphate ions up to a limit determined to be ~6 × 10−3 mol. Akaganéite (β-FeOOH) is a major component of the nanoparticles formed in the absence of structure directors but only present in the very early stages (< 8 h) of particle growth when phosphate is present. The PiFM data suggest a correlation between the areas in which phosphate ions are adsorbed and areas where akaganéite persists on the surface. In contrast, goethite (α-FeOOH) is a directly observed precursor of the hematite nanorods when 1,2-diamino propane is present. The PiFM data shows goethite in the center of the developing particles consistent with a mechanism in which the iron hydroxide re-dissolves and precipitates at the nanorod ends as hematite. SN - 1556-276X UR - https://doi.org/10.1186/s11671-020-03387-w DO - 10.1186/s11671-020-03387-w ID - Allender2020 ER -