Prominently photocatalytic performance of restacked titanate nanosheets associated with H2O2 under visible light irradiation

• An exfoliation-restacking strategy was used.
• The catalyst possesses a porous structure with large surface area.
• The catalyst exhibits a visible light absorption with –OOH modification.
• The catalyst shows much higher activity than P25 and the layered precursor.
• The catalyst has a high stability for dye degradation.

In this work, an extremely high activity for visible light driven photocatalytic degradation of organic dyes was achieved on a restacked titanate nanosheets (rs-TNSs) material with the assistance of hydrogen peroxide (H2O2). The photocatalyst was obtained via exfoliating layered titanate precursor and the following flocculation by acidic solution, and its porous structure was further characterized with these technologies of scan electron microscopy, X-ray diffraction and nitrogen sorption. This rs-TNSs material exhibited prominent activity for photodecomposing Rhodamine B, ~ 90% dyes being removed in the first 5 min, and the photocatalytic efficiency was much higher than those of the layered precursor and commercial Degussa P25 TiO2 under the same condition. The possible mechanism for enhanced photocatalytic activity was proposed: enlargement of the absorption spectrum to visible region by the surface modification of peroxide groups; acceptance of photogenerated electrons by H2O2 to reduce the recombination of electron–hole pairs and produce oxidative species of hydroxyl radicals. Additionally, the influences of H2O2 dosage, dye concentration and the reusability of photocatalyst were further investigated.

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