Facile synthesis of a novel 0D/2D CdS/Bi4TaO8Br heterojunction for enhanced photocatalytic tetracycline hydrochloride degradation under visible light

Abstract

A novel visible light-responsive 0D/2D CdS/Bi₄TaO₈Br nanocomposite photocatalyst was synthesized through the in situ deposition of CdS quantum dots (QDs) on the surface of 2D Bi₄TaO₈Br nanoplates via a hydrothermal synthesis process. The photocatalytic activity of the CdS/Bi₄TaO₈Br heterojunction was evaluated by tetracycline hydrochloride degradation experiments under visible light irradiation. The 0D/2D heterojunction structure caused highly efficient charge separation, and the photocatalytic degradation rate of the optimized CdS/Bi₄TaO₈Br sample reached 81.44%, which is 1.34 times that of pure Bi₄TaO₈Br. Meanwhile, CdS/Bi₄TaO₈Br-200 exhibited the highest kinetic rate of 0.089 L mg⁻¹ min⁻¹, which is 2.69 and 4.08 times that of pure Bi₄TaO₈Br (0.033 L mg⁻¹ min⁻¹) and the sample prepared by the grinding method (0.0218 L mg⁻¹ min⁻¹), respectively. The enhanced degradation activity was attributed to the merits of the 0D/2D structure and type-II heterojunction, which can produce better visible light absorption and generate more active species, affording faster charge separation capacity. Moreover, the CdS/Bi₄TaO₈Br photocatalyst showed good stability in cyclic degradation experiments. The results of this work not only show that the successful design and construction of the 0D/2D CdS/Bi₄TaO₈Br nanocomposite can achieve the efficient photocatalytic degradation of common antibiotics but also propose the idea of 0D/2D heterostructures for the design of high-performance photocatalysts.