Green synthesis of high throughput hydrogen peroxide via sub-atmospheric plasma-water interaction

Plasma-activated water (PAW), enriched with reactive species such as hydrogen peroxide (H₂O₂), presents a sustainable and versatile solution for wastewater treatment, disinfection, agriculture, and biomedical applications. This study investigates the effects of key plasma parameters - treatment time, input power, water purity, and chamber pressure - on H₂O₂ production. A statistical framework combining response surface methodology (RSM), regression analysis, ANOVA, effect estimation, and marginal means was employed to model and analyze these influences. Among the variables, treatment time had the most significant impact, followed by water purity and input power. Deionised water produced higher H₂O₂ concentrations due to reduced ion buffering capacity. Under optimised conditions (3 min, 300 W, 100 mmHg), a maximum H₂O₂ concentration of 35 mg·L⁻¹ was achieved, with an energy efficiency of 42.9 g kWh^-1. Additionally, the energy efficiencies for NO₃-, NO₂-, and dissolved O₃ were 73.5, 14.7, and 6 g kWh^-1, respectively. These findings provide valuable insights for tailoring PAW production toward specific oxidative applications.