Surface modulation of inorganic layer via soft plasma electrolysis for optimizing chemical stability and catalytic activity

Abstract

• Destructive nature of high-energy plasma in water is controlled by modulating EDL. • Porosity of Al 2 O 3 -based inorganic layer is adjustable by soft plasma discharges. • Corrosion is delayed by aluminosilicate compounds with compact structure. • Catalytic activity towards organic dye is enabled via homolytic cleavage of H 2 O 2 . • An optimum combination of chemical stability and catalytic activity is achieved. The present study reports the formation of alumina-based inorganic layer via soft plasma discharges for optimizing chemical stability and catalytic activity together. Alkaline silicate electrolyte with complexing agent is formulated to ‘soften’ the destructive nature of plasma discharges in water. The presence of complexing agent having large denticity activates the swarms of soft plasma events, resulting in a less porous architecture than that with simple structure due to a homogenization of electrical field. Accordingly, such inorganic layer comprises stable aluminosilicate since chemical transformations are facilitated to a greater extent by soft plasma discharges. The conformal inorganic layer in the present work demonstrates protective and catalytic features together on account of a synergy between compact microstructure and dynamic surface topography caused by residual tracks of plasma discharges. The reformation of electrical double layer after disruptive events, which underlines the formation of soft plasma discharges, is discussed on the basis of quantum chemical calculation and impedance analysis.