Biochar nanoparticles (BCN) derived from spruce wood and wheat straw were prepared, characterized incorporated into zinc-rich epoxy coatings, with the aim of improving zinc powder utilization anticorrosion performance. Formulations different BCN commercial carbon black dosages (0.4 wt%, 0.8 wt% 1.6 wt%) compared to a paint (ZRP) without addition. After immersion salt spray exposure, coated stee...