Two novel thiadiazole derivatives as highly efficient inhibitors for the corrosion of mild steel in the CO2-saturated oilfield produced water

•Two thiadiazole derivatives were synthesized as the inhibitors for mild steel.•These inhibitors show good inhibition performance even at fairly low concentration.•These inhibitors act as mixed type ones with predominant anodic effectiveness.•The adsorption of thiadiazole derivatives follows the Langmuir adsorption isotherm.•The theoretical calculations are in good agreement with the experimental results.