Comparison of Enhanced Photocatalytic Degradation Efficiency and Toxicity Evaluations of CeO2 Nanoparticles Synthesized Through Double-Modulation

Abstract

We demonstrated that Fe/Cr doped and pH-modified CeO2 nanoparticles (NPs) exhibit enhanced photocatalytic performance as compared to bare CeO2 NPs, using photocatalytic degradation. To assess the toxicity level of these double-modified CeO2 NPs on the human skin, they were introduced into HaCaT cells. The results of our conventional cellular toxicity assays (neutral red uptake and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide for assays) indicated that Cr@CeOx NPs prompt severe negative effects on the viability of human cells. Moreover, the results obtained by scanning transmission X-ray microscopy and bio-transmission electron microscope analysis showed that most of the NPs were localized outside the nucleus of the cells. Thus, serious genetic toxicity was unlikely. Overall, this study highlights the need to prevent the development of Cr@CeOx NP toxicity. Moreover, further research should aim to improve the photocatalytic properties and activity of these NPs while accounting for their stability issues.

Photocatalysis of bifunctional Cr- and Fe-doped CeO2 nanoparticles toward selective oxidation of 5-hydroxymethylfurfural and decomposition of high-density polyethylene

“…44 Through the Raman pro les, we also con rm that TM ion doping into the CeO 2 NPs barely in uences the CeO 2 structure. The red shift of the prominent F 2g band for Cr@CeO 2 (458 cm -1 ) and Fe@CeO 2 (454 cm -1 ) NPs indicates the incorporation of Cr and Fe ions into the CeO 2 NPs, 40,45 in accordance with the HRTEM and XRD results. The width of the F 2g mode for the TM@CeO 2 NPs is broader than that for the CeO 2 NPs, as shown in Fig.…”

Photocatalysis of Cr- and Fe-Doped CeO2 Nanoparticles to Selective Oxidation of 5-Hydroxymethylfurfural

“…Focusing on the relative intensity between peaks D and E, it can be seen that the D/E intensity ratio of the two TM@CeO 2 NPs is lower than that of the CeO 2 NPs. This indicates that the number of defects in TM@CeO 2 NPs is greater than in the CeO 2 NPs [ 40 , 41 , 42 , 43 ]. To confirm the oxidation state and electronic structure of the TMs formed on the surface of the TM@CeO 2 NPs, we measured the Cr L -edge spectrum for Cr@CeO 2 NPs and the Fe L -edge spectrum for Fe@CeO 2 NPs ( Figure 2 c–d).…”

Antimicrobial Effectiveness of Innovative Photocatalysts: A Review

“…Furthermore, oxygen-doped graphitic carbon nitride microspheres (O-g-C 3 N 4 ) and hydrogen-doped zinc oxide (ZnO(H)) displayed negligible cytotoxicity towards A549 cells [141,147]. Fe/Cr-doped CeO 2 NPs showed negative effects on the aneuploid immortal keratinocyte (HaCaT) cell line [142]. The potential cytotoxic effects of Fe-doped TiO 2 on human endothelial cells (HECVs), red blood cells, hemocytes of Mytilus galloprovincialis, and mouse macrophages (RAW 247) were evaluated, showing a decrease in cell viability only for HECV [143][144][145].Cadmium-bismuth microspheres (CdS-Bi 2 S 3 ) exhibited high cytotoxicity activity against a human colon colorectal tumor (HCT 116) cell line, even at the lowest tested concentration (0.25 g/L; see Table 4) [146].…”