Solid-liquid contact electrification using polyvinyl chloride/activated carbon-NaCl catalyst for tetracycline degradation in water

Abstract

A polyvinyl chloride/activated carbon (AC)-NaCl composite tribocatalyst was used to degrade 89.8 % of tetracycline (TC) at 10 mg L−1 in 120 min. Reactive oxygen species (ROS) generated through solid-liquid contact electrification under mechanical agitation were the degradation drivers. Polyvinyl chloride is a well-known tribocatalytic material. AC formed percolated conductive network, an ‘electron highway’ that enabled rapid charge transport. NaCl induced bipolar charge transport by creating coexisting donor and acceptor pathways that suppress recombination. Charge transport facilitated selective attacks on TC, which is distinct from conventional advanced oxidation processes (AOPs). The catalyst maintained its competitive efficiency after five cycles and after re-synthesis. The TC degradation rate was higher above the critical flow velocity (0.290 m s−1). The energy efficiencies in TC degradation were 210.58 kWh·m−3·order−1 at the critical flow velocity, which was comparable to conventional AOPs (28–214 kWh·m−3·order−1). Tribocatalysis driven by mechanical agitation in water can enable energy-efficient and ROS-selective contaminant degradation