Mingjun Cui1, Yue Yu2, Yuxuan Zheng1. 1. Key Laboratory of Impact and Safety Engineering, Ministry of Education, School of Mechanical Engineering and Mechanics, Ningbo University, Ningbo 315211, China. 2. Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
Abstract
In present study, novel nitrogen doped carbon dots (NCDs) are synthesized using a green material-dopamine-as a precursor and studied as corrosion inhibitors for Q235 carbon steel in 1 M HCl solution. According to the electrochemical results, it is found that NCDs acting as a mixed-type corrosion inhibitor can effectively retard the acid corrosion of carbon steel, and their inhibition efficiency increases with the concentration increasing from 50 to 400 ppm. The highest inhibition efficiency is 96.1% in the presence of 400 ppm NCDs at room temperature. Additionally, the adsorption of NCDs obeys the Langmuir adsorption isotherm. In addition, weight loss results show that the inhibition efficiency in the presence of 400 ppm NCDs increases with prolonged exposure time and rising temperature (298-328 K), owing to the strong adsorption of NCDs on the steel surface, and the η value is 92.2% at 60 h of immersion and 86.2%, 89.1%, 90.6% and 92.9% at 298, 308, 318 and 328 K, respectively. Surface analysis by scanning electron microscope (SEM), laser scanning confocal microscope (LSCM) and X-ray photoelectron spectroscopy (XPS) further proves the formation of a protective NCD film on the steel surface.
In present study, novel nitrogen doped n class="Chemical">carbon dots (NCDs) are synthesized using a green material-dopamine-as a precursor and studied as corrosion inhibitors for Q235 carbon steel in 1 M HCl solution. According to the electrochemical results, it is found that NCDs acting as a mixed-type corrosion inhibitor can effectively retard the acid corrosion of carbon steel, and their inhibition efficiency increases with the concentration increasing from 50 to 400 ppm. The highest inhibition efficiency is 96.1% in the presence of 400 ppm NCDs at room temperature. Additionally, the adsorption of NCDs obeys the Langmuir adsorption isotherm. In addition, weight loss results show that the inhibition efficiency in the presence of 400 ppm NCDs increases with prolonged exposure time and rising temperature (298-328 K), owing to the strong adsorption of NCDs on the steel surface, and the η value is 92.2% at 60 h of immersion and 86.2%, 89.1%, 90.6% and 92.9% at 298, 308, 318 and 328 K, respectively. Surface analysis by scanning electron microscope (SEM), laser scanning confocal microscope (LSCM) and X-ray photoelectron spectroscopy (XPS) further proves the formation of a protective NCD film on the steel surface.