Comparison of a bio-based corrosion inhibitor versus benzotriazole on corroded copper surfaces

•First stratigraphic characterization of a green corrosion inhibitor and benzotriazole.•Benzotriazole formed few BTA-Cu complexes resulting in poor protectiveness.•The green inhibitor converted almost all copper hydroxychlorides into copper oxalates.•The proposed green inhibitor represents an effective alternative to BTA.