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In this work, the MgAl-NO 3 layered double hydroxide (LDH) developed by the single-step in situ growth method is used as a robust sorbent to remove arsenic from aqueous solution. The MgAl-LDH exhibiting two different distinct morphologies (platelet structure and cauliflower-shaped structure) was developed on the AA6082 substrate with the variation in synthesis parameters, where AA6082 specimen acts as both the reactant and support. The structural characterizations were investigated through scanning electron microscopy, X-ray diffraction analysis, and energy dispersion spectroscopy, while the adsorption of arsenic on MgAl-LDH was studied through Langmuir and Freundlich models. The Langmuir isotherms have shown a maximum adsorption capacity of around 213 and 239 mg/g for platelet and cauliflower-like MgAl-LDH, respectively. The pseudo-first-order and pseudo-second-order Lagergren kinetic models were studied for the understanding of the adsorption kinetics. The results depicted that anion exchange and the electrostatic interaction are the possible reasons of arsenic sorption on MgAl-LDH, but the ion exchange mechanism is found to be the dominant mechanism. The maximum adsorption capacity of cauliflower-shaped MgAl-LDH was found to be slightly higher than platelet structure, but overall maximum arsenic adsorption uptake values of both in situ growth structures have found to be exceeded the mostly reported MgAl-LDH maximum adsorption capacities.

In this contribution, new electrocatalyst materials, namely silicon-multiwalled carbon nanotubes (Si/MWCNTs), nitrogendoped multiwalled carbon nano-tubes (Si/NCNTs), and silicon-carbon black (Si/CB), were developed and characterized in an effort to investigate less expensive and more efficient alternatives to Pt-based catalysis for energy storage cells applications. The role of structural behavior of obtained specimens and corresponding electrochemical performances were characterized through X-ray diffraction and scanning electron microscopy, while cyclic voltammetry and electrochemical impedance spectroscopy were analyzed for electrochemical measurements and evaluation of oxygen evolution reaction (OER) along with oxygen reduction reaction (ORR). The electrochemical studies have shown that these materials exhibit reasonable performance for both the ORR and the OER. The findings concluded that the Si/CB base catalyst has shown both OER and ORR activities in comparison to Si/MWCNTs and Si/NCNTs where only ORR performance was monitored. However, Si/NCNTs have shown much higher ORR activity compared to the others. This work highlights the comparison of three possible alternative materials as a potential catalyst to develop optimum alternatives of Pt-free catalysts for fuel cell and lithium-based battery systems.