The use of fluorescent nanomaterials in various fields of study has become increasingly common. In this work, the use of carbon quantum dots as a corrosion marker in carbon steel is proposed. To produce the sensor, carbon quantum dots based on ethylenediamine and citric acid were used, dissolved in a polymeric matrix. The quantum dot used showed a quantum yield of 42.34%. The nanomodified coatings emitted blue light under ultraviolet radiation lamp. However, it was observed that there is a loss of photoluminescence in the coating on the carbon steel substrate compared to the coating on the polymeric substrate, which maintained photoluminescence activity after natural exposure. Thus, it is inferred that the loss of photoluminescence may be associated with the corrosion process.

This study investigates protic ionic liquids (PILs) as corrosion inhibitors for carbon steel in a saline environment, focusing on their influence on the formation and stability of corrosion products during exposure. By examining corrosion product evolution under inhibited conditions, this work provides a mechanistic perspective beyond conventional inhibition efficiency, evaluating whether the resulting corrosion layers can act as a protective barrier during prolonged exposure. X-ray diffraction, Mossbauer, and Raman spectroscopy techniques were applied to characterize the surface and corrosion product. Moreover, optical and scanning electron microscopy techniques (SEM−ED and FIB− SEM) were selected to identify the oxides/oxyhydroxides externally. At the same time, X-ray spectrometers with energy dispersion were used to analyze the elemental composition, mainly O, Fe, N, Cl, and Na. Fundamentally, this preliminary investigation seeks to identify corrosion products (iron oxides/oxyhydroxides), including lepidocrocite, magnetite, and goethite, elucidate their formation mechanisms, and contribute a novel perspective to the corrosion inhibitor literature. In particular, the study focuses on the interaction between carbon steel and Protic Ionic Liquids (PILs), exploring their potential influence on the formation and evolution of distinct oxide phases on the material’s surface. As a key distinguishing feature, the addition of the corrosion inhibitors PILs (2- HEAF) and (2-HDEAF) revealed the presence of a dense and compact goethite, a phase that can aid in blocking chloride penetration, potentially extending the longevity of carbon steel in saline environments. This observation supports the efficacy of these inhibitors, as previously demonstrated in electrochemical and weight-loss experiments, suggesting their potential for long-term corrosion protection.

This academic article investigates the performance of dye-sensitized solar cells (DSSCs), which are affected by various defects like charge recombination, high impedance, and low power conversion efficiency due to complex physicochemical phenomena. The study explores different materials and processes to enhance DSSC performance, with a focus on photoanode development. Tin dioxide, tin chloride II dihydrate, copper oxide, boric acid, and sodium phosphate are utilized to fabricate the photoanodes. A thermal treatment at 450°C for 30 minutes precedes dye assembly on the photoanode surface. Results show that the tin chloride II dihydrate-modified photoanode outperforms others, achieving higher open-circuit voltage (0.50V), current density (9.58 mAcm^-2), fill factor (0.37), and power conversion efficiency (1.77%). The study suggests that tin salt particles positively impact voltage, current, electron transport, and charge separation, enhancing overall cell performance. Charge recombination significantly affects power conversion efficiency and impedance, but accurately quantifying it remains challenging. Lower recombination levels favor efficiency, while higher levels reduce it.

UNS S41003 is a low-cost, low-carbon ferritic stainless steel that exhibits moderate corrosion resistance but limited mechanical performance. This study evaluates the electrochemical behavior of untreated and thermomechanically treated UNS S41003 samples. Corrosion tests were conducted in acidic electrolytes with varying pH to simulate aggressive environments relevant to industrial and structural applications where exposure to acidic media and corrosive pollutants occurs. Potentiodynamic polarization curves for all samples displayed passive regions typically associated with protective oxide film formation; however, localized pitting corrosion was detected post-test. Electrochemical impedance spectroscopy indicated a marked decrease in corrosion resistance as pH decreased. The corrosion resistance of the treated alloy remained comparable to that of the untreated condition, indicating that thermomechanical processing did not detrimentally affect passivity or corrosion performance under the tested conditions. The literature suggests that the applied treatment enhances mechanical properties, supporting the potential use of this alloy in structural components subjected to acidic environments requiring a balance of mechanical strength and corrosion resistance.