Directional charge separation on 2D/2D BiVO4/MXene for the enhanced photoelectrochemical detection of oxytetracycline antibiotic in water

The development of a rapid yet efficient detection method is quite urgently needed to address the growing great human health concerns caused by immoderate emissions of oxytetracycline (OTC) antibiotics in water. This work reports a novel photoelectrochemical (PEC) sensor with 2D/2D BiVO4/Ti3C2 for detecting OTC in water. Through multiple characterizations, the formation of BiVO4/Ti3C2 nanocomposites and their superior photo-electronic activities were confirmed. Under visible light irradiation, when electrons transfer from excited BiVO4 to Ti3C2, small Ti3C2 nanosheets worked as the electron trap sites, resulting in efficiently directional charge separation. The rapid photocurrent responses of BiVO4/Ti3C2 are linearly related to the concentration of OTC in the range of 0.1-200 nM, with the detection limit (LOD) of (S/N = 3) 0.03 nM. In addition, the obtained BiVO4/Ti3C2 sensor possessed good stability, reproducibility and selectivity, providing a great potential in the practical application of OTC detection in water.