Origin of the Visible-Light Response of Nickel(II) Oxide Cluster Surface Modified Titanium(IV) Dioxide

Abstract

Access to the full text of the published version may require a subscription. states, whereas NiO cluster levels are generated near the conduction band minimum 22 of anatase. This is in contrast to the SnO 2 /rutile TiO 2 system, where the density of states near the conduction band minimum 23 increases with the VB unmodified. In the NiO/TiO 2 system, the band gaps of both rutile and anatase are narrowed by up to 0.8 24 eV compared with pristine TiO 2 , which pushes the photoactivity into the visible region. In view of the calculated electronic 25 structure, we have attributed the enhanced photocataltyic activity both to the charge separation due to the excitation from the Ni 26 3d surface sub-band to the TiO 2 conduction band and the action of the NiO species as a mediator for the electron transfer from 27 the TiO 2 conduction band to O 2 . Rights

Design of Novel Visible Light Active Photocatalyst Materials: Surface Modified TiO2

“…Other combined experimental and DFT studies on transition metal oxide modified TiO2 can be found in refs. [89][90][91] and will be discussed in Section 4. Reproduced from [78] , 2013, American Chemical Society For modification of rutile with a CuO nanocluster a new, empty Cu 3d state is present in the VB-CB gap, which arises from the presence of a Cu 2+ oxidation state, with a 3d 9 electronic configuration.…”

“…In experimental work from a number of groups [73,77,78,[89][90][91][92][93][94]102,103,[112][113][114][115][116][117] doped TiO2 system, we consider N-F co-doped TiO2 [118] which shows visible light absorption, but no photocurrent. The surface modification approach has the potential to alleviate some of these issues with doped TiO2.…”

“…The surface modification of TiO2 by these molecular sized comes from photoluminescence results, in which the composite system is excited and emission of light resulting from charge recombination is monitored, e.g. refs [50][51][52]77,78,[89][90][91] . In these studies, while unmodified TiO2 shows significant PL with a characteristic PL emission at ca.…”

Lead oxide-modified TiO2 photocatalyst: tuning light absorption and charge carrier separation by lead oxidation state

“…These properties make TiO 2 suitable as a photocatalyst for water-splitting technology using renewable resource in the form of solar light, 1,2 or for depollution of toxic organic 30 pollutants from the domestic and industry use. [3][4][5] However the band gap of TiO 2 which lies in the range of 3.0 to 3.2 eV (depending on the crystal form) can only absorb in the UV region.…”

“…These new 30 states can function as states into which an electron from the (unmodified) TiO 2 valence band can be excited, thus giving an effectively reduced energy gap when compared to unmodified TiO 2 (again the surface VB-CB energy gap is unchanged upon modification). In this case, the energy gap underestimation with 35 DFT is clearly apparent, as in the largest Pb 4 O 8 nanocluster, the empty Pb states are found ca.…”