Ar–CO2 Mixture Plasma Jet Driven by Nanosecond Pulse at Atmospheric Pressure: Discharge Characteristics and Composition Analysis

The study of plasma with CO2 or its mixtures with other gases is the current interest for reforming CO2 as an environmental pollutant. Most of the investigations of discharge characteristics on Ar–CO2 mixture plasma are mainly driven by the alternating current, while employing the nanosecond pulse to generate plasma still needs to be studied in depth. In this study, we obtain the Ar–CO2 mixture plasma jet by employing nanosecond pulse, and the discharge characteristics and composition analysis at different ratios of CO2 addition in Ar–CO2 gas mixture are evaluated and compared by discharge digital photographs, voltage–current waveforms, intensified charge-coupled device (ICCD) images, emission spectra, and Fourier transform infrared (FTIR) spectra. We found that the plasma jet length decreases with the increase in concentration of CO2 in gas mixture, and the values of positive and negative peak currents are dependent on the CO2 percentage. The possible reason is that it favors CO2 conversion when the CO2 content is below 1% and shows inhibiting effects when the CO2 content is beyond 1%. Furthermore, the percentage of CO2 (under 10%) in gas mixture plays a significant role in the lifetime and intensity of the dynamic plasma plumes. The CO (B-A) angstrom band and the spectra band related to nitrogen (N2) can be recognized in the emission spectra and the generation of CO may be caused by the quenching of OH(A). This study would provide the positive implications for the optimization of the plasma-assisted CO2 decomposition process.