Volume 44, Issue 2, 2026
6th December, 2024
Corrosion Inhibition on Mild Steel using Zinc Phosphating Modified with Magnesium and Calcium Additives
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by Ayoola A. A., Durodola M. B., Babalola R. et al.
85-94
DOI: https://doi.org/10.4152/pea.2026440201
MS is a very versatile and useful alloy in metal industry, since it is available and affordable, but it is prone to corrosion. This study investigated MS corrosion inhibition by modifying Zn₃(PO₄)2 bath with MgO and, then, with combined MgO and CaO additives. Different phosphating times (40, 60 and 80 min) and T (65 and 80 °C) were considered. Ct from 0 to 1.8 g/L MgO and combined MgO/CaO additives were added to Zn₃(PO₄)2 bath. SEM analysis of the coated samples was carried out. The specimens were also immersed in 3.5 wt% NaCl, for WL testing. Obtained results showed that the highest IE(%) of 56% was obtained for the MS sample at a phosphating T of 65 °C and Ct of 1.8 g/L MgO additive. For combined MgO and CaO additive, an IE(%) of 32% was obtained, at 65 °C, with a Ct of 0.9 g/L. MgO and CaO adsorption process (separately and combined) onto MS followed Freundlich’s adsorption model. ΔG indicated a physical adsorption process, and ΔH indicated an exothermic adsorption process, while ΔS during coating revealed a decrease in the process randomness degree.
Keywords: Ca additive; corrosion; Mg additive; MS; Zn phosphating.
Energy Production from Extracting Lignin and Valorization of Agricultural Biomass Waste: Pretreatment and Characterization
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by M. Asif, I. Bashir , G. M. Khan et al.
95-105
DOI: https://doi.org/10.4152/pea.2026440202
This study investigated a method for sustainable energy production which involved extracting lignin from waste Bm (AS, BTB, NTB and WnS), to use it as an energy source. The main goal was to advance alternative resources for producing transportation fuels and commodity chemicals, paving the way for a carbon-emission-free future. A pretreatment procedure was conducted, using methods such as EDX, SEM, TGA, proximate and ultimate analyses, to examine extracted lignin. Herein, WnS displayed the highest Bm-derived lignin Ct. BTB and NTB exhibited highest Ct from S, while, remarkably, AS showed the lowest one. NTB extraction process investigation revealed that minimum and maximum yields, at 2 and 3 h, produced lignin Ct of 6 and 8%, respectively. Similarly, BTB yielded 12 and 13% lignin, after 1 and 2 h, respectively. The study indicated that WnS possessed the highest lignin Ct. Furthermore, it was seen that varying certain parameters increased lignin yield.
Keywords: biofuel; Bm; chemical treatment; green energy; lignin cellulose; production; renewable energy.
Electrochemistry of Azapropazone at a Gold Electrode in a Britton-Robinson Buffer Solution of pH 4.0
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by I. S. El-Hallag, A. A. Al-Owais, S. H. El-Mossalamy et al.
107-118
DOI: https://doi.org/10.4152/pea.2026440203
Herein, accurate voltammetric techniques were used for investigating Aza compound at an Au electrode in an aqueous universal BRB solution with pH 4.0 and at room temperature. Employed voltammetric methods were CV, ConvV and DeconvV, at various SR in the range from 40 to 800 mV/s. DSM was used to confirm experimental electrochemical parameters, and to identify the nature of the electrode reaction mechanistic pathway. Recorded CV revealed an uni-directional irreversible sharp anodic peak (Ep = 0.541 mV) in a BRB with pH 4.0. It indicated that the oxidation process was moderately fast. Electrons consumed in the electrode reaction were two. ConvV and DeconvV supported the presence of a chemical step coupled with electron transfer, due to the absence of the cathodic peak coupled in the reverse scan. Oxidative peak sharpness indicated some Aza adsorption control at the Au electrode surface.
Keywords: Aza; DSM; electrochemical parameters; electrode reaction; voltammetric techniques.
A Novel Heterocyclic Schiff Base: Electrochemical and Antioxidant Investigation
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by Youcef Bellal, Meriem Hamoudi and Samira Ghedjati
119-140
DOI: https://doi.org/10.4152/pea.2026440204
Electrochemical and AA study of a new heterocyclic Schiff base (L1) was herein carried out for the first time. Electrochemical results and AA tests were performed using PDP, in vitro, by ABTS, C40H56/C18H32O2, DPPH and FRAP, respectively. IE(%) of this compound against corrosion of MS, immersed in a KOH simulated concrete solution (pH of 13.5), with 0.8 M Cl-, was investigated. Electrochemical results showed that L1 was a good CI, even at low Ct (from 10-3 to 10-6 M; τinhib > 98%), the best scavenger in DPPH and ABTS (IC50: 0.022 ± 0.00 and 0.003 ± 7.92E-05 μg/mL, respectively), and the most active in C40H56/C18H32O2 test, with a an IE(%) of 80.22 ± 1.58%. L1 exhibited a significant reducing capacity (A0.5: 0.008 ± 0.00 mg/mL) analogous to that obtained for Trolox (A0.5: 0.008 ± 9.14 05 mg/mL). This study demonstrated L1 good IE(%) and AA.
Keywords: ABTS; AA; CI; DPPH; IE(%); L1
Understanding Proton Introduction and Migration in Yttria-Stabilized Zirconia from DFT Calculations and Muon-Spin Spectroscopy
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by A. G. Marinopoulos, R. C. Vilão, H. V. Alberto et al.
141-151
DOI: https://doi.org/10.4152/pea.2026440205
Abstract
YSZ is a compound with an important role in electrochemistry applications, due to its high electrical conductivity. It is commonly used as electrolyte in solid-oxide fuel cells. Several studies have also suggested additional uses of this material as a proton conductor, when grown in Nc form. The present research reports combined theoretical and experimental results that examined the incorporation and properties of proton defect in YSZ. The calculations were based on DFT and NEB methods. MSS was also performed by studying muons evolution, a lighter hydrogen particle with non-zero spin. The results provided vital information on the formation energetics of proton defect, its migration behavior and electronic structure.
Keywords: DFT; MSS; NEB; YSZ.
