Construction of S-scheme g-C3N4/ZrO2 heterostructures for enhancing photocatalytic disposals of pollutants and electrocatalytic hydrogen evolution

Abstract In consideration of environmental protection and energy conversion, the development of semiconductor photocatalytic technology is as first choice. But the photocatalytic performance of typical ZrO2 catalyst is seriously inhibited since it can only been driven by ultraviolet light. Herein, constructing S-scheme g–C3N4–modified ZrO2 heterostructures can be conducive to enhance photocatalytic performance by separating rapidly the photogenerated carriers. In this work, a series of S-scheme g-C3N4/ZrO2 heterostructures were constructed via the simple calcination, and their photocatalytic performances were evaluated by degradating Rhodamine B (RhB), Methyl orange (MO) and Acid orange II (AO II) under visible light irradiation. Importantly, 15% g-C3N4/ZrO2 heterostructures exhibited superior photocatalytic activities (degradating 82% RhB, 50% MO and 98% AO II in 150 min) and electrocatalytic performance (possessing lower overpotential, Tafel slope as well as more exposed active sites). The enhanced performances were ascribed to the intensive light absorption, the larger specific surface area, more exposed active sites as well as the higher separation of photogenerated electrons/holes pairs, which were confirmed by UV–vis diffuse reflectance spectra (DRS), photoluminescence (PL) spectra, electrochemical and radicals trapping experiments. This research provides the platform for the application in environmental protection and energy conversion via constructing S-scheme heterostructures.