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Carbon steel is one of the most widely used alloys in industrial applications. However, the use of this metal may be limited because of corrosion tendency. Thus, it is necessary to develop methods that inhibit its degradation. One way to inhibit corrosion is to use organic inhibitors. Some organic compounds with heteroatoms inhibit corrosion by forming a protective film. In this study, the corrosion inhibition of carbon steel 1020 in 0.1 mol L-1 hydrochloric acid medium was evaluated. The natural inhibitor used was an aqueous extract of the bark of Persea pyrifolia (PP) plant at concentrations of 2.5, 5 and 10% V / V. The electrochemical response was determined by open circuit potential measurements, electrochemical impedance spectroscopy, and anodic potentiodynamic polarization. Therefore, mass loss was measured, and inhibitory efficiency was evaluated. The best results were observed for the concentration of 2.5% V / V of Persea pyrifolia extract, presenting and inhibition efficiency of 82.5% on the 1020 carbon steel. The electrochemical results indicates that PP extract can be used as green corrosion inhibitor in acidic medium. DOI: http://dx.doi.org/10.17807/orbital.v13i2.1469

Renewable energy methodologies are the key to a sustainable future. PV technology has been raised as one of the most promisor alternatives for energy conversion, due to the use of an inexhaustible source. The third generation of solar devices, present in composition a semiconductor oxide, that work as electron transport material (ETL), receiving and transporting the electron from a photosensitive molecule. TiO2 performs with efficiency the role of ETL in solar devices, nevertheless, since of the higher cost, other oxides have been studied, as Nb2O5. This work aims to synthetized Nb2O5 by Pechini methodology and applied it as ETL in a solar device. The techniques performed in particle characterization were Scanning Electronic Microscopy (SEM) and X-ray diffraction (XRD). To verify the capability of transport electrons, the electrochemical measurements were applied to Voc/Jsc decay, j-V curves, Electrochemical Impedance Spectroscopy (EIS), and Intensity Modulate Photovoltage Spectroscopy (IMVS). The results showed Nb2O5 synthesized in orthorhombic phase able to produce a photosensitive dye-solar device with j = 4.18 mA cm−2, V = 825 mV, FF = 0.4, PCE = 1.38% with slow recombination rate when compare to TiO2 dye-solar cell. The IMVS and EIS technique present the same accuracy to electron lifetime determination which is confirmed by the t-test performed.