<p>Nonlinear optical materials are of great interest for applications in photonics, optoelectronics, and advanced nonlinear optical devices. In this work, we synthesized Borophene/TiO₂ nanoparticle nanocomposites with varying Borophene concentrations and systematically investigated their nonlinear optical response. TEM, EDX, XRD, FTIR, and UV-Vis absorption spectroscopy confirmed the successful synthesis of the nanocomposites. The optical bandgap progressively decreases from 3.50&#xa0;eV to 2.90&#xa0;eV with increasing Borophene loading, indicating enhanced light absorption ability of nanocomposites. Nonlinear optical properties were studied through the Z-scan technique using a femtosecond laser centered at 800&#xa0;nm wavelength in two modes: Open and close aperture configurations. The open-aperture measurements reveal reverse saturation absorption behavior of the nanocomposites, which is further supported by TRFS analysis. The nonlinear absorption coefficient (β) increases from 0.188 × 10⁻¹² cm/W for pristine TiO₂ nanoparticles to 0.546 × 10^− 12&#xa0;cm/W at 10 wt% Borophene concentration. Closed-aperture Z-scan results show a negative nonlinear refractive index (n₂), confirming self-defocusing behavior of nanocomposites, with the magnitude rising from 0.691 × 10⁻¹⁷ cm²/W for TiO₂ nanoparticles to 1.569 × 10^− 17&#xa0;cm²/W for the highest Borophene loading. Correspondingly, the third-order nonlinear optical susceptibility (χ⁽³⁾) and figure of merit of the nanocomposites also increase with Borophene concentration, with χ⁽³⁾ improving from 8.07 × 10^− 16 esu for pristine TiO₂ nanoparticles to 23.87 × 10^− 16 esu for 10 wt% Borophene. The findings show that the Borophene/TiO₂ nanoparticles nanocomposites have enhanced nonlinear optical response than pristine materials highlighting the strong potential of the nanocomposites for advanced optoelectronic and nonlinear optical applications.</p>