Low temperature-calcined TiO2 for visible light assisted decontamination of 4-nitrophenol and hexavalent chromium from wastewater
In the present study, alkaline hydrothermally treated titania nanoparticles (TiO 2 -HT) are prepared and followed by calcination at different low temperatures to improve TiO 2 activity under visible light. The prepared photocatalysts (PCs) are characterized by different tools. TiO 2 -HT is scrutiniz...
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Veröffentlicht in: | Scientific reports 2019-12, Vol.9 (1), p.1-9, Article 19354 |
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Sprache: | eng |
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Zusammenfassung: | In the present study, alkaline hydrothermally treated titania nanoparticles (TiO
2
-HT) are prepared and followed by calcination at different low temperatures to improve TiO
2
activity under visible light. The prepared photocatalysts (PCs) are characterized by different tools. TiO
2
-HT is scrutinized for decontamination of para-nitrophenol (PNP) and hexavalent chromium ions (Cr
6+
ions) under simulated sunlight. TiO
2
-HT-300 and TiO
2
-HT-400 PCs have nanosized particle with large surface area of 148 and 116.26 m
2
/g, respectively. Additionally, XRD and FTIR proved formation of nanocrystalline anatase TiO
2
. The different calcined TiO
2
-HT materials show lower adsorption capacity for PNP and Cr
6+
ions. TiO
2
-HT-300 and HT-TiO
2
-400 PCs have higher reduction rate of PNP than that of uncalcined temperature titania (HT-TiO
2
-U) powder. Complete conversion of PNP is achieved at natural pH after 180 min over TiO
2
-HT-300. As well, TiO
2
-HT-300 exhibits a superior photocatalytic removal of Cr
6+
ions. The enhanced photocatalytic efficacy is ascribed to the synergism between higher surface area and particle size (quantum effect) of TiO
2
-HT-300. As results, HO· radicals are the main key active species for the photocatalytic degradation of PNP over TiO
2
- HT-300 PC but contribution of O
2
–
and h
+
holes is minor. The used method for preparation of TiO
2
-HT-300 reduces the cost preparation as well as environmental impact reduction. Finally, low temperature-calcined TiO
2
is promising visible light active and an efficient photocatalyst with lower environmental impact for detoxification of PNP and Cr
6+
ions from water. |
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ISSN: | 2045-2322 2045-2322 |
DOI: | 10.1038/s41598-019-55912-2 |