Eggshell-templated synthesis of PbS/CaCO₃ nanocomposites for ^[rad]CO₃⁻ mediated efficient degradation of tetracycline under solar light irradiation

Photocatalytic degradation reactions have been reported to be mediated by hydroxyl radicals, superoxide radical or photogenerated electrons and holes. The significant role of carbonate radicals in the photocatalytic degradation of carbonate-based materials has been largely ignored to date. Herein, we report carbonate radical mediated photocatalytic degradation of tetracycline hydrochloride by using eggshell-based PbS/CaCO₃, exhibiting a remarkably enhanced photocatalytic activity. This research represents a fundamental breakthrough toward the green synthesis of semiconductors/CaCO₃-based photocatalysts and understanding of significant role of carbonate radical in photocatalytic degradation processes.