Dramatic CO2 photoreduction with H2O vapors for CH4 production using the TiO2 (bottom)/Fe–TiO2 (top) double-layered films

Improving Selectivity and Activity of CO2 Reduction Photocatalysts with Oxygen

“…17,44,45 The primary crystal structures of titania are anatase and rutile, while the electrons of the former structure have a much longer lifetime (1 ms) of the excited state resulting in improved photocatalytic CO 2 reduction. 46 So far, titania-based catalysts with supported Pt, 47 Ag, 48 Au, 49,50 Pd, 51 Cu, [52][53][54][55][56][57][58][59][60][61][62][63][64][65] Fe, 66 or Ni 67 species have been applied for photocatalytic CO 2 reduction. Among the known copper/titanium dioxide (Cu/ TiO 2 ) materials (Table S1), active catalysts in batch or continuous-flow reactors required the presence of Cu(I) species.…”

Recent Advances in Heterogeneous Photocatalytic CO2 Conversion to Solar Fuels

“…Similarly, Kang’s group reported that the absorption bands of x mol % M-TiO 2 (M = Cu, Fe) powders, in which M ions well-inserted into the anatase TiO 2 framework, are shifted to higher wavelengths with enhancing M ion concentration. , The prepared powders were fabricated as the TiO 2 /M-TiO 2 double-layered films for CO 2 reduction, and the CH 4 generated from the photoreduction of CO 2 with H 2 O increases remarkably over the double-layered film. In particular, CH 4 is mostly evolved over the TiO 2 /5.0 mol % Cu-TiO 2 and TiO 2 /1.0 mol % Fe-TiO 2 doubled-layered film with 2 and 7 times higher level of production compared to that on TiO 2 (bottom)/TiO 2 (top) double-layered film, respectively. This study shows that the activity over TiO 2 /M-TiO 2 double-layered films can be enhanced by effective charge separation and inhibited charge recombination due to interfacial transfer between TiO 2 and M-TiO 2 . , …”

“…Introduction of some metal cations (such as Cu, − Co, , Ni, Ce, , Mo, In, Ti, V, and Cr) into the host framework not only modifies the crystallinity of TiO 2 but also influences its light absorption properties. Also, the enhanced red-shifting from the UV region to longer wavelengths in the visible region can be observed with enhancing cation-doping levels. − For example, Cu-doped TiO 2 shows a slightly but steadily decreased bandgap upon enhancing Cu­(II) concentration from 0 to 3 mol % and has the potential to enhance the formation of HCOOH and CO in the presence of sulfide as an electron donor . Ola and Maroto-Valer have reported that the absorption spectra of Cu-based TiO 2 showed an increased shift in the visible light with enhancing Cu loading concentration in comparison with pure TiO 2 .…”

Effective Carbon Dioxide Photoreduction over Metals (Fe-, Co-, Ni-, and Cu-) Incorporated TiO2/Basalt Fiber Films

“…Therefore, the 3d-transition metal ingredients have a beneficial effect on the photocurrent; it plays a role as an intermediate for the efficient separation of photogenerated hole-electron pairs. after 8 h. Generally, CH 4 production from CO 2 reduction with H 2 O can be divided into the following three subprocesses [41]: proton production from H 2 O photodecomposition, CO radical production from CO 2 photo cleavage, and methane production from photosynthesis between the CO radical and proton. The photogenerated electrons on the photocatalysts by UV-radiation induce CO 2 reduction to produce CO 2 radicals, whereas the holes react with the adsorbed H 2 O molecules to perform oxidation.…”