Ultrathin carbon-coated Zr3+-ZrO2 nanostructures for efficient visible light photocatalytic antibiotic elimination

[Display omitted] •Ultrathin carbon-coated Zr3+-ZrO2 composites were synthesized;•Zr3+ species and carbon doping induced visible light absorption;•The samples showed efficient photocatalytic performance;•Active species and possible intermediates were determined;•Possible visible light photocatalytic mechanism was proposed. Broadband solar light absorption and visible light photocatalysis of surface modified ultrawide bandgap semiconductors are receiving wide attentions because of their more negative conduction band potential and positive valence band potential for refractory organics degradation. Here, we reported a novel modified solvothermal strategy by the introduction of distilled water into small molecular alcohols to synthesize crystallized carbon-coated Zr3+-ZrO2 composites for enhanced visible light absorption and visible light photocatalytic tetracycline degradation, in which the distilled water favored for the crystallization of Zr3+-ZrO2 and the formed ultrathin carbon layers derived from the polymerization of small molecular alcohols were contributing to the generation of Zr3+ species and well dispersion of Zr3+ self-doped ZrO2 nanoparticles. The experimental results also showed that carbon-coated Zr3+-ZrO2 composites exhibited enhanced visible light absorption, long-lived charges, efficient visible light photocatalytic performance and good recyclable stability. Besides, possible photocatalytic mechanism and antibiotic degradation pathways over carbon-coated Zr3+-ZrO2 composites under visible light irradiation were also proposed in detail.