This study describes a method to produce silane-capped boron nanoparticles (NPs) based on surface modification of boron NPs with a silane. These silane-capped boron NPs are highly dispersible in liquid hydrocarbon fuels such as decalin, thus can enhance the energy content of liquid fuels. The experimental conditions for surface modification were optimized. Silane-capped boron NPs were characterized by means of various techniques, such as X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA). The results show that the oxide layer resident on the surface of boron NPs is essential to obtain silane-capped boron NPs. The suspension containing silane-capped boron NPs (1 wt%) and decalin are highly stable. No obvious sedimentation was observed even after standing for two months. Silane-capped boron NPs were also stable against air oxidation. The formation mechanism of silane-capped boron NPs was proposed. (C) 2017 Elsevier Ltd. All rights reserved.