| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 46578 | Applied Catalysis B: Environmental | 2011 | 9 Pages |
Two novel ternary nanocatalysts, f-MWCNTs-CdS and f-MWCNTs-Ag2S were successfully constructed by covalent grafting of fourth generation (G4) hyperbranched, crosslinked poly(amidoamine) (PAMAM) to carboxylated multi-walled carbon nanotubes (MWCNTs-COOH) and subsequent deposition of CdS or Ag2S quantum dots (QDs). The structural transformation, surface potential, and morphology of functionalized MWCNTs (f-MWCNTs) and nanocatalysts were characterized by UV–vis spectrophotometer, Fourier transform infrared spectroscopy, powder X-ray diffraction, Raman spectroscopy, thermogravimetric analysis, scanning electron microscopy and energy dispersive spectroscopy. Transmission electron microscopy reveals the effective anchoring of QDs on f-MWCNTs. The catalytic activity of nanocatalysts was evaluated by photodegradation of methyl orange under illumination of UV light. The coupling of MWCNTs, PAMAM and CdS or Ag2S QDs significantly enhanced the catalytic efficiency of nanocatalysts. The rate constants for degradation of methyl orange in presence of nanocatalysts were calculated using the Langmuir–Hinshelwood model. Overall, the excellence in photodegradation was accomplished by hybridizing f-MWCNTs with CdS or Ag2S QDs.
Graphical abstractTwo ternary nanocatalysts, f-MWCNTs-CdS and f-MWCNTs-Ag2S, comprised of multiwalled carbon nanotubes (MWCNTs), poly(amidoamine) and CdS or Ag2S quantum dots were successfully synthesized and examined for their photocatalytic activity. The structural transformation, surface potential, and morphology of functionalized MWCNTs and nanocatalysts were characterized by UV–vis spectrophotometer, Fourier transform infrared spectroscopy, powder X-ray diffraction, Raman spectroscopy, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy and energy dispersive spectroscopy.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Constructed novel nanocatalysts are promising reusable photocatalysts. ► PAMAM dendrimers are very effective in replacing the van der Waals force of pristine MWCNTs. ► Structure of MWCNTs is well retainable after covalent grafting of PAMAM also. ► Presence of PAMAM dendrimers on the surface of MWCNTs was observed by TEM. ► Strong interaction between f-MWCNTs and QDs results in the generation of more active sites.
