BiVO4/Fe/Mt composite for visible-light-driven degradation of acid red 18

• The photocatalytic activity of BiVO4/Fe/Mt and Fe/Mt were studied.
• BiVO4/Fe/Mt showed high photocatalytic activity under visible light irradiation.
• BiVO4/Fe/Mt showed low Fe leaching but high OH generation performance.
• BiVO4 and Fe in BiVO4/Fe/Mt had a synergistic effect in photo-Fenton process.

This work described a strategy for loading bismuth vanadate (BiVO4) on hydroxy-iron pillared montmorillonite (Fe/Mt), in which vanadate and bismuth were successively loaded on Fe/Mt to synthesize a BiVO4/Fe/Mt composite with high photo-Fenton catalytic activity. The structural characteristics of the resulting materials were studied using X-ray diffraction, inductively coupled plasma mass spectrometry, nitrogen adsorption–desorption isotherms, and UV–vis diffuse reflectance spectra. Then, the photo-Fenton catalytic activity of the obtained catalysts was tested using acid red 18 (AR18) as a model contaminant under visible light irradiation. Furthermore, the concentration of hydroxyl radical (OH) was studied by high performance liquid chromatography. The results indicated that BiVO4 loaded not only on the outer surface but also into the interlayers of Fe/Mt. The 8%BiVO4/Fe/Mt composite exhibited high photocatalytic activity, and the decolorization efficiency, TOC removal efficiency of AR18, and the production of OH by BiVO4/Fe/Mt were higher than those by Fe/Mt. The high removal efficiency of AR18 and remarkable OH generation performance by BiVO4/Fe/Mt should be attributed to the presence of BiVO4, which can accelerate the reduction of Fe3 + to Fe2 + by providing photo-induced electrons from BiVO4. In addition, the leached amount of Fe from BiVO4/Fe/Mt was 0.32 mg/L after 180 min reaction, much smaller than that from Fe/Mt (0.66 mg/L). The results of this work suggest that the introduction of semiconductor materials may be a feasible way for enhancing the photo-Fenton catalytic activity of heterogeneous photo-Fenton catalysts.

Figure optionsDownload as PowerPoint slide