NOVELTY - An aqueous solution of soluble titanium compound is prepared. A morphology-controlling agent and/or alpha -hydroxy carboxylic acid (I), alpha -hydroxy carboxamide (II) or alpha -amino acid (III) are introduced into the aqueous solution at an acid or carboxamide-to-titanium molar ratio of 0.02-0.2. Titanium dioxide seeds are introduced into the solution, and maintained at 60-80 degrees C for 1-3 hours. The temperature of the stirred solution is elevated to 100 degrees C to refluxing temperature. The reaction mixture is cooled, separated and dried, to obtain rutile titanium dioxide nanoparticles.    USE - Preparation of rutile titanium dioxide nanoparticles. Uses include but are not limited to ultraviolet blocking application, photocatalysis application, biomass conversion applications, lithium ion battery, fuel cell, photovoltaic application and photonic applications.    ADVANTAGE - The method enables preparation of rutile titanium dioxide nanoparticles having high surface area, refractive index and ultraviolet blocking capability.    DETAILED DESCRIPTION - An aqueous solution of soluble titanium compound having titanium concentration of 0.5-1 moles/L is prepared optionally in the presence of a mineral acid. A morphology-controlling agent and/or alpha -hydroxy carboxylic acid of formula: R-CH(OH)COOH (I), alpha -hydroxy carboxamide of formula: R-CH(OH)CONH2 (II), or alpha -amino acid of formula: R-CH(NH2)COOH (III) are introduced into the aqueous solution at an acid or carboxamide-to-titanium molar ratio of 0.02-0.2 while simultaneously heating the solution at 60-80 degrees C with constant stirring. Titanium dioxide seeds is introduced into the stirred solution at seed-to-titanium dioxide molar ratio of 0.0005-0.0015, and the stirred solution is maintained at 60-80 degrees C for 1-3 hours. The temperature of the stirred solution is elevated to 100 degrees C to refluxing temperature, and maintained for 2-4 hours. The reaction mixture is cooled to room or ambient temperature, cooled reaction mixture is optionally neutralized, separated and dried, to obtain rutile titanium dioxide nanoparticles which are aggregates of elongated titanium dioxide crystallites.    R=alkane, alkene, alkyne, arene or 6C or more cycloalkane.    An INDEPENDENT CLAIM is included for rutile titanium dioxide nanoparticles, which are ordered acicular aggregates of elongated titanium dioxide crystallites having thickness of 3-5 nm in which one end of each of elongated titanium dioxide crystallites are joined into a cluster such that the opposite ends of each of the elongated titanium dioxide crystallites extend outwardly in the shape of a nano-sized funnel structure having diameter of 50 nm, and height of 50-100 nm.