Heteropolyacids-Immobilized Graphitic Carbon Nitride: Highly Efficient Photo-Oxidation of Benzyl Alcohol in the Aqueous Phase
| Autor: | Sai An, Lifu Wu, Yu-Fei Song |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Environmental Engineering
General Computer Science Materials Science (miscellaneous) General Chemical Engineering Energy Engineering and Power Technology Heteropolyacids 02 engineering and technology 010402 general chemistry Photochemistry 01 natural sciences Catalysis Benzaldehyde chemistry.chemical_compound Trifluorotoluene Phosphotungstic acid Photocatalysis General Engineering Graphitic carbon nitride 021001 nanoscience & nanotechnology 0104 chemical sciences chemistry Benzyl alcohol lcsh:TA1-2040 0210 nano-technology Selectivity lcsh:Engineering (General). Civil engineering (General) |
| Zdroj: | Engineering, Vol 7, Iss 1, Pp 94-102 (2021) |
| ISSN: | 2095-8099 |
| Popis: | Benzaldehyde is a highly desirable chemical due to its extensive application in medicine, chemical synthesis and food sector among others. However, its production generally involves hazardous solvents such as trifluorotoluene or acetonitrile, and its conversion, especially selectivity in the aqueous phase, is still not up to expectations. Hence, developing an environmentally benign, synthetic process for benzaldehyde production is of paramount importance. Herein, we report the preparation of a photocatalyst (PW12-P-UCNS, where PW12 is H3PW12O40·xH2O and P-UCNS is phosphoric acid-modified unstack graphitic carbon nitride) by incorporating phosphotungstic acid on phosphoric acid-functionalised graphitic carbon nitride (g-C3N4) nanosheets. The performance of PW12-P-UCNS was tested using the benzyl alcohol photo-oxidation reaction to produce benzaldehyde in H2O, at room temperature (20 °C). The as-prepared PW12-P-UCNS photocatalyst showed excellent photocatalytic performance with 58.3% conversion and 99.5% selectivity within 2 h. Moreover, the catalyst could be reused for at least five times without significant activity loss. Most importantly, a proposed Z-scheme mechanism of the PW12-P-UCNS-catalysed model reaction was revealed. We carefully investigated its transient photocurrent and electrochemical impedance, and identified superoxide radicals and photogenerated holes as the main active species through electron spin-resonance spectroscopy and scavenger experiments. Results show that the designed PW12-P-UCNS photocatalyst is a highly promising candidate for benzaldehyde production through the photo-oxidation reaction in aqueous phase, under mild conditions. |
| Databáze: | OpenAIRE |
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