Examples of the voltage and current waveforms for discharges in both liquid and gas are shown in Fig. 2.
All reactors (Fig. 3) consisted of a 17.3 cm diameter glass vessel fitted with an airtight polymer cap, which was adapted to allow for sample extraction, solution recirculation, and integration of the electrodes. The reactors were operated in semi-batch mode, with liquid recirculating at 1.4 L/min. The liquid recirculation loop ensured thorough mixing and included a heat exchanger to keep the solution at 15 C. The headspace was purged with argon at 2.1 L/min.