Poly (ionic liquid-co-acrylic acid)/oxidized carbon nitride (P/P/O) with enhanced photocatalytic and synergistic bacteriostasis performance

Abstract

Overconsumption of non-renewable energy sources has caused the energy crisis and environmental pollution. Photocatalytic technology can utilize solar energy as a driving force for the energy conversion. Herein, 1-vinyl-3-ethylimidazolium tetrafluoroborate (VEImBF₄) and acrylic acid (AA) were used as monomers to prepare poly(1-vinyl-3-ethylimidazolium tetrafluoroborate-co-acrylic acid/ oxidized carbon nitride) (P/P/O) by in situ radical copolymerization with oxygenated graphite carbon nitride (OCN). Specifically, the molecular structure, optical properties, photocatalytic removal of organic pollutants and photocatalytic bacterial inhibition were investigated for different P/P/O ratios. The results showed that P/P/O exhibited excellent light absorption and a high electron-hole separation rate. In addition, it also showed superior photocatalytic removal of MB ability with great cycle stability. Considering the effects of AA and OCN contents on the inhibition performance, P/P/O-2 exhibited the optimal bacteriostatic effect. It can effectively inhibit the growth of E. coli and S. aureus under visible light excitation, which showed the excellent synergistic inhibition performance. The diameters of the inhibition zone of P/P/O-2 on E. coli and S. aureus reached 21.49 mm and 22.36 mm, respectively. Meanwhile, the inhibition rate of P/P/O-2 on E. coli and S. aureus in 24 h reached 98.57 % and 98.59 %, respectively. Simultaneously, the minimum inhibitory concentration (MIC) for E. coli and S. aureus was 0.0469 mg/mL, at the same time, the inhibitory activity of P/P/O was concentration-dependent and broad-spectrum. Therefore, P/P/O with enhanced photocatalytic performance demonstrated its application potential in the field of photocatalytic bacteriostatic or self-cleaning.