Preparation and Characterization of Ce/N-Codoped TiO2 Particles for Production of H2 by Photocatalytic Splitting Water Under Visible Light

Abstract

Cerium and nitrogen codoped TiO 2 photocatalysts were successfully prepared by sol-gel method. The results showed that Ce doped in TiO 2 could prevent phase transition of anatase to rutile and inhibit the growth of crystallite. In addition, Ce and N codoped in TiO 2 enhanced the lattice distortion. N-Ti bond and N-Ti-O bond were formed in codoped titania, which narrowed the energy gap and extended the absorption edge to the visible light range, and the synergistic effects of the Ce and N codoped samples made the red shift more distinct. The results showed that the rate of hydrogen production was the best for the sample prepared under the conditions of the content of Ce doped for 0.6% (molar ratio) and calcination temperature of photocatalyst preparation at 500°C.

Au/TiO2-CeO2 Catalysts for Photocatalytic Water Splitting and VOCs Oxidation Reactions

“…In this case, the substitution of cerium ions (Ce 3+ and Ce 4+ ) in the TiO 2 framework, as suggested by DRS measurements, was the key factor for having a good performance. The cerium defects act, in fact, as hole traps [39,40,63], avoiding the recombination of active electrons and holes and thus favoring the reduction of water. In this case, gold positively affects the photocatalytic performance, both increasing the defective structure of ceria, as shown by Raman, and favoring the enrichment of ceria on the surface of TiO 2 , as shown by EDX, thus explaining the highest H 2 production rate of the Au/TiO 2 -10%CeO 2 system.…”

Preparation and Characterization of Ce/N-Codoped TiO2 Particles for Production of H2 by Photocatalytic Splitting Water under Visible Light by Sun et al. (Catal Lett (2010) 135:219)

“…XPS analysis is of useful application to the much studied class of Ce-bearing catalysts [2][3][4][5], because it provides straightforward access to the chemistry of the cerium, and this is also a central issue in both the scope and aims of Sun et al's paper [1]. My comment will focus on the authors' interpretation of the XPS Ce3d spectra of sample Ce(1.2%)-N-TiO 2 analyzed as-inserted (Fig.…”

“…In a recent paper, Sun et al reported on the preparation and characterization of cerium-nitrogen-doped TiO 2 photocatalysts, and used X-ray photoelectron spectroscopy (XPS) to map the oxidation state of the chemical elements present therein [1]. XPS analysis is of useful application to the much studied class of Ce-bearing catalysts [2][3][4][5], because it provides straightforward access to the chemistry of the cerium, and this is also a central issue in both the scope and aims of Sun et al's paper [1].…”

“…My comment will focus on the authors' interpretation of the XPS Ce3d spectra of sample Ce(1.2%)-N-TiO 2 analyzed as-inserted (Fig. 7a of their paper [1]) as well as after being subjected to visible-light irradiation to test its photo-catalytic behavior (Fig. 7b).…”

“…They claim that the peaks at binding energy (BE) values of *882 and 898.2 eV in the 5/2 and 3/2 components, respectively, indicate the presence of CeO 2 -like species, whereas the peaks at *885.5 and 904 eV indicate the presence of Ce 2 O 3 -like species. In other words, Sun et al claim that both spectra contains two spinorbit-split (5/2;3/2) peak pairs deriving from tetravalent to trivalent cerium oxidic species [1]. The only difference between the two spectra concerns their profile, which the authors interpret as arising from the fact that ''the peak area ratio of Ce 4?…”