Hexamine was used as a fuel for the first time to synthesize BaFe12O19 materials under different pH (2, 6, 8, 10 and 12) condition. Though all the combustion products exhibited mixed phases of mainly γ-Fe₂O₃ and BaCO₃, the annealed (1000 °C for 2 h) powders yielded good quality hexagonal BaFe12O19 phase materials. The optical properties of these materials were investigated by Fourier-transform infrared (FT-IR), near-infrared (NIR), and photoluminescence (PL) spectroscopic techniques. Plate-like shaped sticks/rods of nanometric (~33 to 40 nm) edge sizes of particles are observed for the present BaFe12O19 materials. A considerable improvement in NIR reflectivity of BaFe12O19 materials is noted for the present method than the mechano-thermal solid-state synthesis. The thermal analysis (TGA) and ferromagnetic hysteresis loop (M-H) measurements reveal an important change in weight and magnetic parameters, respectively due to variation in pH. It is found that the present pristine BaFe12O19 materials have feeble antibacterial activity as compared to the reported nanocomposite consists of cotton fabric coated with BaFe12O19 nanoparticles against Gram-negative Pseudomonas aeruginosa bacterium.