Photocatalytic reduction of CO2 with H2O over modified TiO2 nanofibers: Understanding the reduction pathway
- 787 Downloads
Nanosized metal (Pt or Pd)-decorated TiO2 nanofibers (NFs) were synthesized by a wet impregnation method. CdSe quantum dots (QDs) were then anchored onto the metal-decorated TiO2 NFs. The photocatalytic performance of these catalysts was tested for activation and reduction of CO2 under UV-B light. Gas chromatographic analysis indicated the formation of methanol, formic acid, and methyl formate as the primary products. In the absence of CdSe QDs, Pd-decorated TiO2 NFs were found to exhibit enhanced performance compared to Pt-decorated TiO2 NFs for methanol production. However, in the presence of CdSe, Pt-decorated TiO2 NFs exhibited higher selectivity for methanol, typically producing ∼90 ppmg−1·h−1 methanol. The CO2 photoreduction mechanism is proposed to take place via a hydrogenation pathway from first principles calculations, which complement the experimental observations.
KeywordsTiO2 photocatalysis CdSe quantum dots CO2 photoreduction
Unable to display preview. Download preview PDF.
- Metz, B.; Davidson, O.; De Coninck, H.; Loos, M.; Meyer, L. Carbon Dioxide Capture and Storage; Cambridge University Press: Cambridge, UK, 2005.Google Scholar
- European Parliament Legislative Resolution of 17 December 2008 on the Proposal for a Directive of the European Parliament and the Council on the Promotion of the Use of Energy from Renewable Source (COM(2008)0019-C6-0046/ 2008-2008/0016(COD)); European parliament: Strasbourg, France, 2008.Google Scholar
- Yamashita, H.; Fujii, Y.; Ichihashi, Y.; Zhang, S. G.; Ikeue, K.; Park, D. R.; Koyano, K.; Tatsumi, T.; Anpo, M. Selective formation of CH3OH in the photocatalytic reduction of CO2 with H2O on titanium oxides highly dispersed within zeolites and mesoporous molecular sieves. Catal. Today 1998, 45, 221–227.CrossRefGoogle Scholar
- Pathak, P.; Meziani, M. J.; Li, Y.; Cureton, L. T.; Sun, Y. P. Improving photoreduction of CO2 with homogeneously dispersed nanoscale TiO2 catalysts. Chem. Commun. 2004, 1234–1235.Google Scholar
- Sarkar, A.; Shchukarev, A.; Leino, A.-R.; Kordas, K.; Mikkola, J.-P.; Petrov, P. O.; Tuchina, E. S.; Popov, A. P.; Darvin, M. E.; Meinke, M. C. et al. Photocatalytic activity of TiO2 nanoparticles: Effect of thermal annealing under various gaseous atmospheres. Nanotechnology 2012, 23, 475711.CrossRefGoogle Scholar
- Liu, Y.; Zhou, S.; Li, J. M.; Wang, Y. J.; Jiang, G. Y.; Zhao, Z.; Liu, B.; Gong, X. Q.; Duan, A. J.; Liu, J. et al. Photocatalytic reduction of CO2 with water vapor on surface La-modified TiO2 nanoparticles with enhanced CH4 selectivity. Appl. Catal. B: Environ. 2015, 168–169, 125–131.CrossRefGoogle Scholar
- Liu, L. J.; Li, Y. Understanding the reaction mechanism of photocatalytic reduction of CO2 with H2O on TiO2-based photocatalysts: A review. Aerosol Air Qual. Res. 2014, 14, 453–469.Google Scholar
- Wu, M.-C.; Sápi, A.; Avila, A.; Szabó, M.; Hiltunen, J.; Huuhtanen, M.; Tóth, G.; Kukovecz, Á.; Kónya, Z.; Keiski, R. et al. Enhanced photocatalytic activity of TiO2 nanofibers and their flexible composite films: Decomposition of organic dyes and efficient H2 generation from ethanol–water mixtures. Nano Res. 2011, 4, 360–369.CrossRefGoogle Scholar
- Giannozzi, P.; Baroni, S.; Bonini, N.; Calandra, M.; Car, R.; Cavazzoni, C.; Ceresoli, D.; Chiarotti, G. L.; Cococcioni, M.; Dabo, I. et al. Quantum espresso: A modular and opensource software project for quantum simulations of materials. J. Phys.: Condens. Mat. 2009, 21, 395502.Google Scholar
- Swope, R. J.; Smyth, J. R.; Larson, A. C. H in rutile-type compounds: I. Single-crystal neutron and X-ray diffraction study of H in rutile. Amer. Mineral. 1995, 80, 448–453.Google Scholar
- Landmann, M.; Rauls, E.; Schmidt, W. G. The electronic structure and optical response of rutile, anatase and brookite TiO2. J. Phys.: Condens. Mat. 2012, 24, 195503.Google Scholar