Constructing mesoporous Zr-doped SiO onto efficient Z-scheme TiO/g-CN heterojunction for antibiotic degradation via adsorption-photocatalysis and mechanism insight.

Novel modified-TiO/Zr-doped SiO/g-CN ternary composite is fabricated via an in-situ grow of porous Zr-SiO layer to TiO/g-CN heterojunction, which exhibits well adsorption-photocatalytic performance under simulated solar light irradiation. The nano-size mesoporous TiO are dispersed on the lamellar g-CN, and the Zr-SiO is in-situ fabricated onto the surface of g-CN sheets. The adsorption occurs on the SiO layers, and doping Zr element to SiO enhances the adsorption of pollutants, while the photocatalytic reaction occurs on the valence band (VB) of TiO and conduction band (CB) of g-CN, which gives reactive oxygen species of ∙O, h, and ∙OH for high efficient decomposition of antibiotics, i.e. berberine hydrochloride (98.11%), tetracycline (80.76%), and oxytetracycline (84.84%). The excellent adsorption capacity and Z-scheme photoinduced charge carrier migration behavior endowed the novel material with enhanced berberine hydrochloride (BH) removal in water, which approximately 2.5 and 3.8 folds than that of pure g-CN and sole TiO, respectively. Three degradation pathways are unraveled by LC-MS and theoretical calculations. Furthermore, the toxicity of intermediates was evaluated by the Toxicity Estimation Software Tool (T.E.S.T.), the result demonstrated a good application potential of M-TiO/Zr-SiO/g-CN as an novel adsorptive photocatalyst.