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The detection and removal of Atrazine (ATZN), a pesticide of environmental concern, requires more efficient methods to facilitate its degradation. The adequate structural morphology, high specific surface area, great photothermal conversion performance, higher amount of oxygenated functional groups, and intense and stable fluorescence signals are considered as favorable properties of the materials used in the in the proposal of physicochemical methods for detection, capture and degradation of nitrogenous herbicides. Herein, the design, preparation, and characterization of MnFe2O4@CDs as a dual-functional material is reported. Due to its optical, photothermal, textural and surface chemistry properties, the material is able to capture, detect, and degrade the herbicide "Atrazine" in synthetic samples. The preparation of the proposed composites, formed by particles of bimetallic oxides (Mn-Fe2O4) and a covering of carbon dots (CDs), was confirmed using various characterization techniques including SEM, TEMHR, RAMAN, FTIR, UV-Visible, Photoluminescence, DRX, N2 adsorption-desorption isotherms, superficial chemistry, and photothermal. The study revealed that the ATZN capture occurs through hydrogen bonding interaction between −COOH and −COH functional groups exposed on CDs surface and amine groups −NH− of the herbicide. Furthermore, the CDs behave as fluorescent markers of single-channel employed to detect ATZN and to monitor the capture-degradation process. The MnFe2O4@CDs composite was integrated as the main thermoactive material into a photothermal reactor on which was incident a NIR laser. The high near-infrared absorption of the Mn-Fe2O4 particles resulting in an efficient photothermal conversion; which in turn, increase the temperature of the surrounding medium. The increase in temperature promotes the activation of persulfate (PS) at the interface of the MnFe2O4@CDs−PS system producing SO4• − radicals as oxidizing agents of atrazine. Our results demonstrate that the process may effectively degrade 99 % of atrazine for a concentration of CATZN [20 mM], when NIR light irradiated by 45 min and the system reaches a temperature of ca. 53 ºC. Additionally, the degradation of ATZN was confirmed by analysis of total organic carbon (TOC). The fluorometric analytical assay by CDs-base fluorescence probes allowed following the FL signal at 520 nm(λexit = 375 nm) for the capture “turn on” and degradation “turn off” of atrazine. Finally, as a comparison, we highlight the significant efficiency shown by the process studied here, compared to other similar atrazine degradation processes previously reported. 

The copper corrosion was studied for 30 days in two alkaline electrolytes: saturated Ca(OH)2 and cement extract, employed to simulate concrete-pore environments. Electrochemical Impedance Spectroscopy (EIS) and Cyclic Voltammetry were carried out at the open circuit potential (OCP), and potentiodynamic polarization (PDP) curves were performed for comparative purposes. Electrochemical current fluctuations, considered as electrochemical noise (EN), were employed as non-destructive methods. The tests revealed that sat. Ca(OH)2 is the less aggressive to the Cu surface, mainly because of the lower in one order pH. In consequence, the OCP values of Cu were more positive, the polarization resistance values were higher by one order of magnitude, and the anodic currents of Cu were lower than those in the cement extract. The analyzed EN indicated that the initial corrosion attacks on the Cu surface are quasi-uniform, resulting from the stationary persistent corrosion process occurring in both model solutions. XPS analysis and X-ray diffraction (XRD) patterns revealed that in sat. Ca(OH)2, a Cu2O/CuO corrosion layer was formed, which effectively protects the metallic Cu-surface. We present evidence for the sequential oxidation of Cu to the (+1) and (+2) species, its impact on the corrosion layer, and also its protective properties.