Novel methods for determination and manipulation of surface charges performed on an atmospheric DBD microplasma

Abstract In photo- and electrocatalysis it is already well-established that surface charges can alter chemical adsorption and reaction paths of the catalyst. However, the novel realm of plasma catalysis lacks experimental exploration regarding the impact of plasma-induced surface charges on catalytic processes. This paper paves the way by introducing a straightforward method for precisely charging the dielectric (catalyst) in a dielectric barrier discharge microplasma at atmospheric pressure. It additionally enables the determination of this surface charge avoiding artifacts or volume charge interference. Through pre-charging of the dielectric, the charges’ impacts on re-ignition and forming of charge equilibria during the discharge are investigated. Moreover, a laser-assisted operando technique is introduced to generate up to 15% of either positive or negative additional surface charges (compared to the default operation) within <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mn>3.5</mml:mn> <mml:mstyle scriptlevel="0"/> </mml:mrow> </mml:math> μs after irradiation and potential for even higher yields. The charges’ origin and the plasma’s response to these laser-induced surface charges are explored.