CuOx–TiO2 junction: what is the active component for photocatalytic H2 production?

Abstract

CuOx based junctions e.g. CuOx-TiO2 have been demonstrated to be very effective in photocatalytic H2 production, but the active component at the junction is less understood. We herein report that an as-prepared CuOx-TiO2 photocatalyst undergoes an in situ restructuring process during photocatalytic H2 production under solar light irradiation to form the active Cu2O-TiO2 interfacial structure on the surface. These results unambiguously demonstrate that Cu2O is the active copper species in CuOx-TiO2 photocatalysts.

Cu2O/Reduced Graphene Oxide Composites for the Photocatalytic Conversion of CO2

“…The XPS peak that corresponds to Cu 2+ is much higher than that in the Cu 2 O sample treated under an Ar atmosphere (Figure 3 d). As a result of the more positive conduction band of CuO, the relatively high amount of CuO inevitably results in deteriorated photocatalytic activity for CO production, which agrees well with previous results 25, 33…”

H2 production by photocatalytic reforming of oxygenated compounds using TiO2-based materials

“…These results highlight the central role of Cu(0) as real co-catalyst during operation of the photocatalytic H 2 production. Although many studies reported the presence of CuO and/ or Cu 2 O as active co-catalysts [41][42][43][44], the oxidation state of Cu assessed by XPS could be affected by re-oxidation of Cu(0) nanoparticles and/or by the difficulty in discriminate the position of Cu 2p 3/2 position for Cu 2 O and Cu [42,45]. HAADF-STEM revealed that the mean particle size of Cu nanoparticles (Fig.…”

Cu–TiO2 systems for the photocatalytic H2 production: Influence of structural and surface support features

“…In spite of that obtained rates for these alternative transition metal based systems are still far from those obtained for noble metals, copper based catalysts appear as a promising candidate [16][17][18][19][20]. It can be stated that the origin of the photoactivity for the H 2 production reaction of copper-based systems is strongly affected by the complex structural, morphological, and chemical features of copper species [21].…”

“…Traditionally, highly active photocatalysts are based on TiO 2 doped with noble metal ions (Pt, Au, Pd) acting as co-catalysts for charge trapping sites and avoid the electron-hole recombination processes [6][7][8][9][10]. Due to the high cost of such co-catalysts, transition metal doping with Cu, Fe, Co or Ni have recently turned as a promising option [11][12][13][14][15][16][17][18].…”