Energy-saving piezoelectric pipe functionalized by C3N5/polyvinylidene fluoride composites for enhanced degradation of ciprofloxacin

•The technology is green, energy-saving, pollution-free and recyclable.•The synergistic effect of C3N5 and PVDF enhanced the piezocatalytic performance.•The degradation efficiency of ciprofloxacin was 93% under ultralow water-flow.•The water-flow driven degradation system showed ultra-low energy consumption.