Dynamic growth of rhombic dodecahedral Cu₂O crystals controlled by reaction temperature and their size-dependent photocatalytic performance

Abstract

Compared with low-index {100} or {111} planes of Cu2O crystals, rhombic dodecahedra (RD) Cu2O crystals exposing 12 {110} facets exhibit the most superior photodegradation of organic pollutants.

Size Effect of Cu Nanoparticles in Cu/g-C3N4 Composites on Properties for Highly Efficient Photocatalytic Reduction of CO2 to Methanol

“…Furthermore, as given in Table S1, the bandgap ( E g ) of composites calculated with the Kubelka–Munk equation suggested that the E g of CuCN- T s was reduced with loading Cu NPs, resulting in the boosting number of photoexcited charges . After carefully comparing the calculated E g , we also found that the E g slightly decreased with the increase of solvothermal temperature; in other words, it decreased with the increase of Cu NP size, confirming that the size effect of Cu NPs influence E g to a certain extent. , A similar phenomenon was also reported in previous works, which may be attributed to the high conduction band and the depressed valence band. , Nevertheless, it should be noted that the introduction of Cu particles does not display a significant impact on E g , which may be ascribed to the too-low loading of Cu (1–2%). This suggests that all of the photogenerated electrons produced by materials with smaller Cu NPs have higher energy, which provides a stronger thermodynamic driving force for reducing carbon dioxide to methanol.…”

Hydroxyl ions: flexible tailoring of Cu2O crystal morphology

“… 43 Specially, the ratio of the peak intensity of (220) peak to that of the (200) facet significantly differ between the various particles, suggesting the growing fractions of {110} facets. 15 …”

“…43 Specially, the ratio of the peak intensity of (220) peak to that of the (200) facet signicantly differ between the various particles, suggesting the growing fractions of {110} facets. 15 The average crystal size of the resulting microcrystals are calculated, as shown in Table S2, † which are according to the Debye-Scherer formula (D ¼ 0.89l/b cos q, where l is the X-ray wavelength (1.5418 Å), q is the Bragg diffraction angle of the peak, and b is the peak width at half maximum). 44 To determine the chemical compositions of the obtained Cu 2 O crystals and to identify the chemical state of Cu in the samples, wide-range and high-resolution XPS spectra were obtained, and only Cu and O were observed in the spectra (Fig.…”

“…3,4 As a p-type semiconductor with direct band-gap of 2.17 eV, cuprous oxide (Cu 2 O) is a perspective material, 5 which is widely applied in solar energy conversion, 6 catalysts, 7 gas sensors, 8 templates 9 and antibacterial activity. 10 Shape-controlled synthesis of Cu 2 O crystals has attracted much attention in recent years, and Cu 2 O crystals with different morphologies have been successfully synthesized, such as cubes, 11 octahedra, 12 hollow spheres, 13 tetrapods, 14 rhombic dodecahedra, 15 hollow octadecahedra, 16 etc. for their specic properties and corresponding potential applications.…”

“…Shape-controlled synthesis of Cu 2 O crystals has attracted much attention in recent years, and Cu 2 O crystals with different morphologies have been successfully synthesized, such as cubes, 11 octahedra, 12 hollow spheres, 13 tetrapods, 14 rhombic dodecahedra, 15 hollow octadecahedra, 16 etc. for their specific properties and corresponding potential applications.…”