Biomimetic Guided Bi(2)WO(6)/Bi(2)O(3) Vertical Heterojunction with Controllable Microstructure for Efficient Photocatalysis

To bridge the technical gap of heterojunction induction control in conventional semiconductor photocatalysts, a method of regulating the growth of heterojunctions utilizing biomimetic structures was designed to prepare a series of Bi(2)WO(6)/Bi(2)O(3) vertical heterojunction nanocomposites for the disposal of environmentally hazardous tetracycline wastewater difficult to degrade by conventional microbial techniques. Porous Bi(2)O(3) precursors with high-energy crystalline (110) dominant growth were produced using the sunflower straw bio-template technique (SSBT). Bi(2)WO(6) with a (131) plane grew preferentially into 2.8 to 4 nm pieces on the (110) plane of Bi(2)O(3), causing a significant density reduction between Bi(2)WO(6) pieces and a dimensional decrease in the agglomerated Bi(2)WO(6) spheres from 3 μm to 700 nm since Bi(2)WO(6) grew on the structure of the biomimetic Bi(2)O(3). The optimal 1:8 Bi(2)WO(6)/Bi(2)O(3) coupling catalyst was obtained via adapting the ratio of the two semiconductors, and the coupling ratio of 1:8 minimized the adverse effects of the overgrowth of Bi(2)WO(6) on degradation performance by securing the quantity of vertical heterojunctions. The material degradation reaction energy barrier and bandgap were significantly reduced by the presence of a large number of vertical heterojunction structures, resulting in a material with lower impedance and higher electron–hole separation efficiency; thus, the degradation efficiency of 1:8 Bi(2)WO(6)/Bi(2)O(3) for tetracycline hydrochloride reached 99% within 60 min. In conclusion, this study not only successfully synthesized a novel photocatalyst with potential applications in water pollution remediation but also introduced a pioneering approach for semiconductor-driven synthesis.