One-Pot Construction of Porous WO3/g-C3N4 Nanotubes of Photocatalyst for Fast and Boosted Photodegradation of Rhodamine B and Tetracycline

WO3/C3N4 porous nanotubes (WO3/CNNT) with direct Z-scheme heterojunction have been developed through an effortless one-pot calcination self-assembly strategy. The synthesized -WO3/CNNT heterojunction structure is different from conventional bulk g-C3N4 according to field-emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS) spectra analysis, and has a better performance in photocatalytic degradation of pollutants. It is under a unique structure with an elevated interfacial area and high dispersion active sites, which can facilitate the degradation of some dye pollutants and antibiotics by heterojunctions, higher than that of bulk g-C3N4 and hollow g-C3N4 nanotubes. The photocatalytic experimental results indicated the optimum photocatalyst of the 2% -WO3/CNNT sample with a BET surface area of 108.8 m(2)/g, which can rapidly remove Rhodamine B (RhB) and tetracycline (TC) up to 97.4% and 87.4%, respectively, under visible-light irradiation, which was about 3.4 and 83.8 times higher than that of individual CNNT and WO3 for RhB degradation. Additionally, the degradation of TC was around 1.1 and 14.3 times superior to that of individual CNNT and WO3. Furthermore, the porous WO3/CNNT heterojunction turned out to be stable and reusable after four cycles of experiments. Reactive free radical trapping experiments confirmed that holes (h(+)) and superoxide (center dot O-2(-)) radicals are the most dominant species during photodegradation. Finally, a possible Z-scheme catalytic mechanism is proposed. In this work, some new insights are provided to design novel Z-scheme g-C3N4-based heterojunction photocatalysts with a porous nanotube structure and enhanced photocatalytic performance for high-efficiency degradation of dyes and antibiotics. [GRAPHICS] .

Automated summary

WO3/C3N4 porous nanotubes (WO3/CNNT) with direct Z-scheme heterojunction were synthesized through a one-pot calcination self-assembly strategy. The synthesized -WO3/CNNT heterojunction structure exhibited better photocatalytic degradation performance for pollutants compared to conventional bulk g-C3N4. The optimized 2% -WO3/CNNT sample showed significantly enhanced degradation of Rhodamine B and tetracycline under visible-light irradiation, and the porous WO3/CNNT heterojunction demonstrated stable and reusable properties.