Room-Temperature Thermal Cycling Driven Pyro-Catalysis over g-C3N4/ZnO Composites for Efficient Dye Degradation

A highly efficient pyro-catalytic system based on a g-C3N4/ZnO composite has been developed for dye degradation under near-room-temperature thermal cycling (25–60 °C). This system integrates pyroelectric charge generation with electrochemical redox reactions. The g-C3N4/ZnO for pyro-catalytic Rhodamine B (RhB) dye decomposition with 95.6% efficiency in the dark, whereas pristine g-C3N4 reached only approximately 60.1% under identical conditions. The degradation mechanism is primarily driven by the in situ generation of superoxide (•O2−) and hydroxyl (•OH) radicals, as verified by radical quenching experiments. The formation of the composite facilitates the efficient spatial separation of pyroelectric-induced charges, thereby endowing g-C3N4/ZnO with a significantly enhanced pyro-catalytic performance compared to g-C3N4 alone. This study demonstrates the promising application of g-C3N4/ZnO as a high-performance pyro-catalyst under mild thermal conditions, offering a sustainable and light-independent strategy for wastewater treatment by utilizing ambient temperature fluctuations.