Bi2WO6 Nanosheets Decorated with ZnO Nanorods in 3D Hierarchical Heterostructures: Surfactant-Free Synthesis for Enhanced Visible-Light-Driven Photocatalytic Degradation

Aiming to develop efficient photocatalysts with targeted charge transfer pathways, ZnO/Bi₂WO₆ Z-scheme heterojunctions were synthesized via a one-step surfactant-free hydrothermal method. The optimized composite (ZnO:Bi₂WO₆ = 0.3:1) exhibits a 3D hierarchical structure comprising ZnO rods anchoring on Bi₂WO₆, nanosheets, leading to a high surface area (48.2 m²/g) and abundant surface oxygen vacancies, This unique configuration drives a hole-dominated Z-scheme charge transfer mechanism, where photogenerated holes directly oxidize tetracycline (TC) without relying on secondary radical mediation, achieving 98.1% TC degradation within 90 min (rate constant k = 0.04278 min^–1, 2.9 times the rate of pure Bi₂WO₆). The composite also degrades Rhodamine B (RhB) (97.3%) and Methylene blue (MB) (95.1%) effectively, demonstrating versatile pollutant removal capability, the enhanced charge separation was confirmed by a photocurrent density 10 times higher than that of pure Bi₂WO₆, and the efficiency remained at 89% after four cycles. And it has the advantage of scalable synthesis. This work provides new insights into designing direct Z-scheme systems for practical environmental remediation.

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