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Abstract
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-Charge carrier recombination and wide band gap energy are still the main challenges in the visible-lightdriven
photocatalytic applications of titanate perovskites, ATiO3. Herein, three strategies are rationally
used to achieve a titanate-based photocatalyst with high photocatalytic performance under visible light.
In the first step, SrTiO3, ZnTiO3, and CdTiO3 perovskites were synthesized and their photocatalytic activity
was evaluated in the degradation of methylene blue (MB) and bisphenol A (BPA). Then, a dysprosium
cation (Dy3+) was doped into an ATiO3 crystalline lattice. Systematic investigations indicate that Dy doping
in SrTiO3 and CdTiO3 extends the ligand to metal charge transfer absorption edge to visible wavelengths
leading to the activation of doped perovskites under visible light. Higher visible-light-driven photocatalytic
performance (73.29% for MB and 52.57% for BPA) and higher total organic carbon (TOC) removal (59.20%
for MB and 39.53% for BPA) have been achieved by Dy doped CdTiO3 compared to other photocatalysts.
Finally, we prepared a Dy-CdTP/ZnS QD mesoporous type-II heterostructure by the in situ growth of ZnS
QDs on a flower-like Dy-CdTP. This design accelerates the separation and transfer of photogenerated
electron–hole pairs. The surface area of the Dy-CdTP/ZnS QD heterostructure was ∼11.6 times greater
than that of Dy-CdTP, offering a large surface area for the adsorption of organics, and abundant active
sites for photocatalytic degradation. Taking advantage of the large surface area and considerable suppressing
of the charge carrier recombination, the optimized Dy-CdTP(0.6)/ZnS QD photocatalyst exhibits
excellent and stable performance for the degradation of MB (98.25%) and BPA (89.12%) with their considerable
mineralization under visible light.
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