Investigation of zinc epoxy coatings modified with pyrolyzed and gasified biochar nanoparticles for corrosion protection

Pyrolyzed and gasified biochar nanoparticles (BCN) were manufactured and incorporated into a series of zinc epoxy coatings to investigate how the anticorrosive performance is affected. Electrochemical measurements were conducted to test the coating alongside the exposure. Overall, BCN-modified formulations exhibited enhanced barrier protection, especially on formulations with lower zinc content (10 vol% and 22 vol%). More than 600 h of efficient galvanic protection was found on the gasified BCN-modified formulation with 30 vol% zinc. BCN improved the zinc utilization rate as well, where the unreacted zinc was reduced from ca. 50 wt% to ca. 20 wt% after 930 h of immersion. Scanning electron microscopy and X-ray diffraction results also verified the effects. The enhancement was attributed to the filling of micropores and extra electrical connections provided by BCN. This study imparts a sustainable solution for enhancing the anticorrosive performance of zinc epoxy coatings.