Boron-doped carbon nanoparticles synthesized via laser pyrolysis: Structural characterization and voltammetric evaluation toward energy storage applications

This study employs continuous CO₂-laser pyrolysis to synthesize boron-doped carbon nanoparticles and probes how precursor chemistry (ethylene/acetylene) and pressure (350–950 mbar) influence their structure and electrochemical behavior. Powders were Soxhlet-purified, then examined by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and electron microscopy (SEM/TEM, SAED, HRTEM). The measurements indicate near-spherical nanoparticles (<50 nm) arranged in a single graphitic phase with (002)/(101) reflections and d₀₀₂ ≈ 0.35 nm, specific surface areas up to ~120 m 2 /g, and a lower defect density after purification. Boron appears both substitutionally (B C) and in oxidized environments (BC₂O/BCO₂, B₂O₃); at the same time, the removal of sassolite (boric acid) is established, leading to cleaner nanoparticles and more wettable surfaces. Electrochemically, all samples exhibit electric double-layer capacitor (EDLC) behavior in 0.5 M H₂SO₄ (0–0.8 V vs Ag/AgCl) without redox peaks. The acetylene-derived sample at 750 mbar (BC-AC-750) maintains the most rectangular cyclic voltammograms and strong rate retention, delivering 11.1 F g −1 at 10 mV s −1 and 8.7 F g −1 at 80 mV s −1 . All these results demonstrate that CO₂-laser pyrolysis is an efficient method for producing boron-doped carbon nanoparticles suitable for high-power supercapacitor electrodes.