Thickness-Controlled Graphene Hybrid Interface for HighlyEnhanced Photocatalysis

• Main Authors: Cheng-Chi Kuo, 郭承冀
• Other Authors: Chun-hu Chen
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/54531323866026428836

碩士 === 國立中山大學 === 化學系研究所 === 102 === Graphene has been widely studied in hybrid nanocomposites catalyst because of its unique chemical and electrical properties. However, the enhancement mechanisms in photocatalysis of graphene hybrid catalyst with respect to the number of stacked graphene sheets have not been systematically studied before. In this work, we fabricated a graphene stacking hybrid film (GSHF) comprised of controlled number of stacked graphene layer and photoactive semiconductors (TiO2, ZnO) to investigate the variation of photocatalytic activities. Three layer graphene stacked GSHF exhibits the highest dye-degradation rate constant (k = 0.002 min-1) than other GSHF. With an order of photocatalysis rate constant：3L-GSHF > 5L-GSHF > 1L-GSHF > 7L-GHSF > TiO2 (or ZnO), we found the interface properties of conductivity; surface energy and transmittance of graphene were not the main reasons to affect the photocatalytic activities. The results show that the thickness of graphene plays an predominant role in photocatalytic performance of GSHF. To verify the thickness graphene affect, we demonstrated a photo-assisted Au deposition to label the photocatalytically active sites on GSHF surface. The FE-SEM results of Au-deposited GSHF show that 3L-GSHF has the largest Au density than 1L-GSHF and 7L-GSHF. We propose that the main reason that determines photodegradation activity is graphene energy levels quantization at different stacking thickness. Enhancement factors of surface enhanced Raman spectra (SERS) confirm that 3L-GSHF has the largest amount of photocatalytic sites than 1L-GSHF or 7L-GSHF. We revealed that photocatalytic activities of graphene hybrid nanocomposites can be directly controlled by the thickness of graphene.