ABSTRACT Boron-doped TiO2 (B-TiO2) particles were prepared via the sol-gel approach. The structural and optical properties of the particles were characterised by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), diffuse reflectance spectroscopy (DRS), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), dynamic light scattering (DLS) and transmission electron microscopy (TEM). The response surface method (RSM) was used to optimise the activity of B-TiO2 catalysts for degradation of landfill leachate. It was found that the B-TiO2 has a larger BET surface areas, improved crystallinity, and more intense absorbance in the UV range than has TiO2 (P25 Degussa). Consequently, the photocatalysis degradation of the landfill leachates by B-TiO2 was much higher than that by pure TiO2. Moreover, the kinetic constant of a B-TiO2 photocatalyst was ca. 41% higher than that of pure TiO2.