One-pot synthesis of Ag-MWCNT@TiO2 core?shell nanocomposites for photocatalytic reduction of CO2 with water under visible light irradiation

Meei Mei Gui, William Wong, Siang-Piao Chai, Abdul Rahman Mohamed

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    Abstract

    This work presents for the first time the preparation of silver (Ag)-doped MWCNT@TiO2 (multi-walled carbon nanotubes@titanium dioxide) core?shell nanocomposites with enhanced visible-light-responsive properties for the application in carbon dioxide (CO2) photoreduction. Comprehensive study was conducted on the synthesis and the photoreactivity performance of the Ag-MWCNT@TiO2 ternary nanocomposites at various Ag loadings ranging from 1 to 4 wt (gram Ag per unit gram of TiO2). The properties of the Ag-MWCNT@TiO2 nanocomposites were characterized thoroughly and their photoreactivity was tested in a continuous CO2 photoreduction system under the irradiation of visible light source. The developed Ag-MWCNT@TiO2 demonstrated excellent activity in the reduction of CO2 into methane and ethylene. 2 wt of Ag was found to be the most suitable loading, giving the highest total methane and ethylene formation of ca. 6.34 lmol/g-catalyst and 0.68 lmol/g-catalyst, respectively, for a reaction time span of 7.5 h along with the maximum hourly formation rate of methane and ethylene of ca. 0.91 lmol/g-catalyst/h and 0.048 lmol/g-catalyst/h, at the reaction time of 7th and 6th h, respectively. The results showed that the methane yield over 2 wt Ag-MWCNT@TiO2 nanocomposites was approximately 1.60 folds higher than that of the undoped-MWCNT@TiO2 core?shell nanocomposites.
    Original languageEnglish
    Pages (from-to)272 - 278
    Number of pages7
    JournalChemical Engineering Journal
    Volume278
    Issue numberOctober 2015
    DOIs
    Publication statusPublished - 2015

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