Facile mechanochemical modification of g-C3N4 for selective photo-oxidation of benzyl alcohol

Abstract

Graphitic carbon nitride enriched with ZnO or Fe2O3 were synthesized using a simple one-pot mechanochemical method. By using this method, composite samples were synthetized without the production of any potentially hazardous waste. The synthesized materials were used as catalysts during the selective photo-oxidation of benzyl alcohol. Both composite materials displayed an enhancement of the activity and benzaldehyde selectivity with respect to the pure g-C3N4. The most active catalyst was Fe2O3/g-C3N4. The conversion and benzaldehyde selectivity of this sample were 20 and 70 %, respectively. It showed a considerable increase of the benzaldehyde selectivity compared to the pure g-C3N4 and TiO2 P25 commercial reference. A complete structural and electronic characterization using Scanning Electron Microscopy-Energy Dispersive (SEM-EDX), BET measurements, X-ray diffraction (XRD), X-ray Photoelectron (XPS), and UV-visible spectroscopies was carried out. The characterization analysis pointed out the leading role of the crystallinity and surface concentration over the activity and benzaldehyde selectivity of the reaction.

Effect of Substituents on Partial Photocatalytic Oxidation of Aromatic Alcohols Assisted by Polymeric C3N4

“…This implies the formation of a surface substrate-metal oxide complex and its excitation under visible light, without activating an electron ejection from the valence band (VB) to the conduction band (CB) of the photocatalyst itself. [12][13][14] Despite water is considered as a desirable reaction medium from the point of view of sustainability, still, the major part of selective photo-oxidation reactions is carried out in organic solvents, [15,16] not only because most of the organic molecules are insoluble or scarcely soluble in water, but also because water does not permit an easy control of the reaction pathway. In fact, the formation of highly oxidative hydroxyl radicals readily occurs on the surface of inorganic semiconductor photocatalysts having high VB potential.…”

Advances in mechanochemical processes for biomass valorization

“…Recently, graphitic carbon nitride (g-C 3 N 4 ) doped with zinc oxide or iron oxide were prepared using a one-step mechanical-assisted protocols [23]. The oxide incorporation on graphitic carbon nitride was obtained by a simple mechanical-assisted step in a planetary ball mill for 10 min at 350 rpm.…”

α−Fe2O3 Nanoparticles/Porous g−C3N4 Hybrids Synthesized by Calcinations of Fe‐based MOF/Melamine Mixtures for Boosting Visible‐Light Photocatalytic Tetracycline Degradation

“…Nevertheless, the short lifetime of photo‐generated charge carriers and small hole diffusion length greatly hinder the widespread application of α−Fe 2 O 3 in photocatalysis . In the past several years, the coupling of g−C 3 N 4 with α−Fe 2 O 3 has been an effective route to enhance themselves′ visible‐light photocatalytic activity in various fields such as pollutant degradation, hydrogen production, CO 2 reduction, organic synthesis, and nitrogen fixation . Due to the appropriate band positions of α−Fe 2 O 3 and g−C 3 N 4 , the strong interfacial coupling of α−Fe 2 O 3 /g−C 3 N 4 hybrids largely promoted the transfer and separation of photoinduced charge carriers by common or even Z‐scheme modes, directly accounting for their high photocatalytic efficiency.…”