Structural and Thermal Characterization of Boron-Doped Nano TiO2: Hydrothermal Synthesis for Flame-Retardant Nanomaterials

In this study, the structural, morphological, and thermal effects of doping nano-sized titanium dioxide (TiO2) with two distinct boron sources—boron oxide (B2O3) and boric acid (H3BO3)—were systematically investigated. Synthesis was performed via the hydrothermal method in a PTFE-lined autoclave reactor at 200 °C for 4 hours. Comprehensive characterization of the resulting nanomaterials was conducted using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and thermogravimetric/differential scanning calorimetry (TGA/DSC) analysis. XRD results confirmed that the TiO2 matrix retained its anatase crystal structure in both doping approaches. SEM images revealed grain sizes in the range of 96–97 nm for boron oxide-doped samples and 96–111 nm for boric acid-doped samples. EDS confirmed the successful integration of dopant elements (B, O, Ti) into the structure. TGA/DSC data verified endothermic phase transitions at ~228 °C for B2O3-doped samples and below 200 °C for H3BO3-doped samples, fully consistent with the B2O3–H2O phase diagram. The findings demonstrate that boron doping renders TiO2 nanostructures a promising material for flame-retardant textile applications.