Degradation of formaldehyde by photo-Fenton process over n-ZVI/TiO catalyst.

The degradation of formaldehyde in a photo-Fenton reaction was studied using n-ZVI/TiO as the catalyst. The effects of %n-ZVI loading, catalyst dosage, HO, and pH on formaldehyde degradation were studied. The n-ZVI/TiO catalysts were prepared by impregnation with chemical reduction, and their catalytic activity was evaluated in a batch reactor under UVC light. Transmission electron microscopy (TEM) was used to determine that the n-ZVI nanoparticle size was 39.41 nm. X-ray photoelectron spectroscopy (XPS) was used to study the oxidation states of 2%n‑ZVI/TiO, and the Fe 2p spectrum of 2%n-ZVI/TiO indicated the presence of Fe. The optimal conditions for the complete removal of formaldehyde within 30 min were an n-ZVI loading of 2 wt.%, a catalyst dosage of 0.5 g/L, 30 mM HO, and an initial pH of 3. After the reaction, the C-H functional group of formaldehyde was not observed due to the OH radicals generated by Fe and HO attacking the formaldehyde molecule. Moreover, no Fe leaching was observed, presenting an advantage compared with homogeneous Fe catalysts. Therefore, 2%n‑ZVI/TiO shows excellent potential as a photo-Fenton catalyst for the environmentally friendly degradation of formaldehyde.