Interface-driven WO3-ZnO-g-C3N4 nanoheterostructures for electrochemical monitoring of trimethoprim and visible-light photocatalytic remediation of organic pollutants.

A novel WO3-ZnO-g-C3N4 ternary nanoheterostructure was successfully prepared through a simple hydrothermal method followed by thermal annealing, forming a well-defined heterostructure, together with intimate contact and good crystallinity. The main novelty of the present study is to rationally design a multifunctional WO3-ZnO-g-C3N4 nanoheterostructure to explore its simultaneous electrochemical sensor detection and visible-light-driven photocatalytic degradation functions. It turned out that the WO3-ZnO-g-C3N4-modified glassy carbon electrode achieved remarkable electrochemical performance for the detection of trimethoprim (TMP) with a low limit of detection of 1.27 × 10-7 M, a wide linear response range of 1.43 × 10-7 to 9.23 × 10-7 M, high selectivity and well electrochemical stability. In addition, the synthesized nanocomposite displayed an excellent electrocatalytic oxidation efficiency against TMP oxidation. On the other hand, the WO3-ZnO-g-C3N4 nanoheterostructure showed an outstanding visible-light-driven photocatalytic activity to decolorize methylene blue by 96.5% under irradiation for 80 min. The improved performance in electrochemical sensing and Photocatalytic activity can be ascribed to the well-formed WO3-ZnO-g-C3N4 heterostructure, thus enhancing visible-light harvesting and the coupled effect due to intrinsic interfacial interaction between WO3-, ZnO and g-CN constituents. These findings propose a WO3-ZnO-g-C3N4 nanoheterostructure as a promising noble-metal-free and cost-effective multifunctional material to monitor contamination and clean pollutants in water bodies, which also offers an inspired design strategy for high-performance heterostructured materials.