High-quality two-dimensional (2D) nanosheets of B4C were synthesized using a facile combustion reaction with a reaction mixture comprising boron oxide (B2O3), magnesium (Mg), and polyvinylchloride (C2H3Cl)(n). The ability to tune the nanosheets of boron carbide was achieved by controlling the combustion temperature within a range of 1500-1700 degrees C and by using polyvinylchloride powder as the carbon source. FE-SEM and TEM images of the acid leached combustion products show sheet-like B4C particles with thicknesses of about 10-50 nm and edge lengths from 0.1 to several micrometers. The chemistry of the combustion process and the formation mechanism of B4C nanosheets are discussed based on the experimental findings. (C) 2015 Elsevier B.V. All rights reserved.