Photocatalytic reduction of CO2 with SiC recovered from silicon sludge wastes

• Published in: Environmental technology Vol. 36; no. 23; pp. 2987 - 2990
• Main Authors: Yang, T.-C, Chang, F.-C, Peng, C.-Y, Wang, H. Paul, Wei, Y.-L
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 02-12-2015; Taylor & Francis Ltd
• Subjects: acetic acids; carbon dioxide; catalysts; crystallites; formic acids; hydrogen; lighting; NMR; Nuclear magnetic resonance; nuclear magnetic resonance spectroscopy; photocatalytic reduction of CO; recovery of SiC; Scanning electron microscopy; silicon; silicon carbide; Sludge; X-ray diffraction
• ISSN: 1479-487X; 0959-3330; 1479-487X
• DOI: 10.1080/09593330.2014.960474

In the present study, silicon carbide (SiC) recovered from silicon sludge wastes is used as catalysts for photocatalytic reduction of CO ₂. By X-ray diffraction, it is clear that the main components in the silicon sludge wastes are silicon and SiC. The grain size of the SiC separated from the sludge waste is in the range of 10–20 µm in diameter (observed by scanning electron microscopy). By solid state nuclear magnetic resonance, it is found that α-SiC is the main crystallite in the purified SiC. The α-SiC has the band-gap of 3.0 eV. To yield C ₁–C ₂ chemicals from photocatalytic reduction of CO ₂, hydrogen is provided by simultaneous photocatalytic splitting of H ₂O. Under the light (253–2000 nm) illumination, 12.03 and 1.22 µmol/h g cat of formic and acetic acids, respectively, can be yielded.