Synthesis and characterization of titanium dioxide based ternary nanocomposites for photocatalytic hydrogen production
Titanium dioxide based photocatalysts of different graphene oxide (GO) and silver nanoparticle (AgNP) content were prepared and tested in catalytic methanol reformation reaction. Aqueous suspensions of the composite solids obtained by heterocoagulation of alkaline exfoliated GO suspension and slight...
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| Dokumentumtípus: | Könyv része |
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2016
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| Sorozat: | Proceedings of the International Symposium on Analytical and Environmental Problems
22 |
| Kulcsszavak: | Fotokatalízis - előadáskivonat, Fizikai kémia - előadáskivonat |
| Online Access: | http://acta.bibl.u-szeged.hu/56137 |
| Tartalmi kivonat: | Titanium dioxide based photocatalysts of different graphene oxide (GO) and silver nanoparticle (AgNP) content were prepared and tested in catalytic methanol reformation reaction. Aqueous suspensions of the composite solids obtained by heterocoagulation of alkaline exfoliated GO suspension and slightly acidic TiO2 suspension showed enhanced sedimentation rate at pH = 6.5- 7, when they contained less than 2 wt% graphene oxide. This enables easier catalyst recovery but the suspension needs to be stirred strongly during the catalytic run in order to achieve homogeneous light distribution within the reaction vessel. The catalytic runs were performed in 6 V/V% methanol/water mixture using 500 mg/L catalyst under UV-illumination. The activity of pure titanium dioxide (Degussa P25) continuously increases and reaches a saturation plateau after 150 min with an activity of 0.12 mmol H2/(h×gcat). Incorporation of GO into the titanium dioxide matrix by heterocoagulation method results in aggregated suspensions exhibiting an enhancement of the hydrogen evolution rate to the saturation value of 0.17 mmol H2/(h×gcat). Deposition of different amounts of AgNPs of different sizes onto the surface of titanium dioxide resulted in an even higher photocatalytic activity, reaching 0.25-0.29 mmol H2/(h×gcat). The combination of AgNP’s and GO platelets to obtain ternary TiO2 based catalysts has not shown any further increase of hydrogen generation rate. |
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| Terjedelem/Fizikai jellemzők: | 424 |
| ISBN: | 978-963-306-507-5 |