Facile synthesis of N-doped carbon dots (N-CDs) for effective corrosion inhibition of mild steel in 1 M HCl solution

Abstract

N-CDs, as a novel and eco-friendly inhibitor, were synthesized easily by hydrothermal carbonization technique aiming to inhibit mild steel corrosion in 1 mol. L − 1 HCl. XRD, TEM, SEM, FTIR, UV-vis spectrophotometer and photoluminescence (PL) were utilized to characterize N-CDs. Potentiodynamic polarization and electrochemical impedance spectroscopy techniques along with the complementary surface studies were combined to investigate the corrosion inhibition capability of N-CDs for MS. N-CDs were found nanometer-sized (≈ 4 nm) with quasi-spherical morphology and high crystallinity. Inhibition e ciency, directly proportional to concentration but inversely with temperature, was measured as high as 96.73% (PDP) and 95.21% (EIS) at 200 mg. L − 1 . Inhibition mechanism refered mainly to adsorption process that good obeyed Langmuir adsorption isotherm. The surface studies, quantitatively veri ed by EDX, showed a smoother surface of MS in presence of the N-CDs. Furthermore, the UV-visible spectroscopy effectively revealed the complexations between iron and metal surfaces. IntroductionRecently, designing materials at nanoscale has acquired fundamental applications in many elds starting from everyday life to space innovation. Materials at the nanoscale have extraordinary physical, chemical, electrochemical, mechanical, thermal and biological properties due to their nanoscale size, surface and quantum impacts, that allow to manufacture stronger, harder, biocompatible, and highly corrosion-resistant materials with a wide range of applications in biomedicine, diagnosis, electronics, agriculture, food, pharmaceuticals, energy harvesting for self-powered nano systems, chip fabrication, batteries, fuel cells, corrosion protection of materials, aerospace materials, cosmetics, etc. [1] Among nanomaterials are carbon dots (C-Dots) which plays an important role in nanoscience and nanotechnology since its discovery in 2004 due to their exceptional properties like high uorescencence, water solubility and biocompatibility, low toxicity, and extra small sizes in the range 1-10 nm [2-4]. The subsequent extensive studies gradually revealed the potential applications of C-Dots including anti-counterfeiting [5], optoelectronics [6], uorescence imaging both in vitro & in vivo [7-9], solar cells [10], nanosensing both in vitro & in vivo [8, 11-13], light-emitting devices [14], photocatalysis [11], drug delivery [15], diagnosis of diseases [16], etc. Since 2017, the carbonization of either synthetic and natural organic compounds give rise to the carbon nanodots that revolutionized the eld of metals corrosion inhibition [17-21]. Next work deals with synthesis of C-Dots by the traditional, eco-friendly hydrothermal carbonization method. The properties exhibited by C-Dots depend on the C-sources and conditions used in the synthesis.Most industrial equipment like engineering vehicles, reaction vessels and packaging machineries made from metallic products are inclined to corrosion. One of the most e cient ways of relieving corrosion process is usin...

One-Pot Synthesis of Green-Emitting Nitrogen-Doped Carbon Dots from Xylose

“…The IR spectrum presented five main bands, located at 3118 cm −1 , 3018 cm −1 , 2802 cm −1 , 1726 cm −1 , and 1388 cm −1 . The bands that appeared at 3118 cm −1 and 3018 cm −1 corresponded to the N-H vibration bands [40][41][42] of the two N species present on the CDs, amine/pyrrolic N and graphitic N, respectively. On the other hand, the 2800 cm −1 band could be assigned to the vibration of the C-H bond and the 1388 cm −1 band to its In order to support the XPS results and to confirm the presence of N inclusions and the carboxylic functionalization of the surface of CDs, the Fourier-Transform Infrared (FTIR) spectrum of the sample was recorded (Figure 3).…”