Development and mechanism study of Cu-doped carbon dots as corrosion inhibitor and bactericide

To tackle the critical and multifaceted challenges of metal corrosion in oil and gas operations, a novel green corrosion inhibitor—copper-doped carbon dots (CuCDs)—was synthesized. The results demonstrate that CuCDs exhibit superior corrosion inhibition efficiency (84.20% at 150 mg/L) compared to non-copper-doped carbon dots (NCDs, 70.22% at 200 mg/L), with statistical significance confirmed by triplicate experiments (p < 0.05). Notably, CuCDs also show exceptional antibacterial activity against sulfate-reducing bacteria (SRB), achieving an 88% sterilization rate, which significantly mitigates microbial-induced corrosion. Electrochemical and surface analysis revealed that CuCDs form a denser protective layer on N80 steel, attributed to synergistic chemical and physical adsorption mechanisms. These findings highlight the dual-functional potential of CuCDs as a sustainable solution for simultaneous corrosion and microbial control in oilfield applications.