Graphitic carbon nitride photocatalysis: the hydroperoxyl radical role revealed by kinetic modelling

Abstract

Metal-free graphitic carbon nitride (GCN) is an optical semiconductor with the advantage of in situ H2O2 generation parallel to pollutant removal. The photocatalytic degradation mechanism using GCN is attributed to...

Boosting Carbon Nitride Photoactivity by Metal-Free Functionalization for Selective H2O2 Synthesis under Visible Light

“…Without any sacrificial agent ( i.e ., lack of an oxidation-prone molecule), the photocatalytic reaction is halted due to a fast recombination rate. The photogenerated holes may react directly with available electrons faster than the reaction of oxygen reduction. , …”

“…The photogenerated holes may react directly with available electrons faster than the reaction of oxygen reduction. 107,108 By adding increasing amounts of IPA in the aqueous solution (Figure S9), it is possible to observe an increase in the production of H 2 O 2 until 90% IPA/water, ascribed to a higher availability of protons 109,110 and an increased solubility of oxygen. 111 The partial oxidation of IPA releases protons that will aid the photocatalytic process, by offering the required hydrogen component for H 2 O 2 production, besides reducing the recombination process through an increase of holeoxidation.…”

Metal peroxides as potential photocatalysts for environmental remediation

“…E CB of synthesized metal peroxides as shown in Table S2† proves that synthesized metal peroxides can donate e − to O 2 to form ·O 2 − . 32 Valence band XPS and DRS suggest that these metal peroxides in aqueous suspensions could generate large amounts of ROS and hence could function as better photocatalysts comparing other wide band gap semiconductors (TiO 2 , ZnO) 33,34 esp. in terms of rates of degradation.…”

Structural Effects of Metal Single-Atom Catalysts for Enhanced Photocatalytic Degradation of Gemfibrozil

“…These tests suggest an oxidative mechanism as the principal route for gemfibrozil degradation. In summary, the C 3 N 4 photocatalytic mechanism leads to the generation of reactive oxygen species from the aqueous media, for example, OH • or O 2 •– , via the transfer of excited electrons to the metal centers, which then partake in the degradation of gemfibrozil (Figure b,c) . These species are well-known to facilitate oxidative chemistry.…”

“…In summary, the C 3 N 4 photocatalytic mechanism leads to the generation of reactive oxygen species from the aqueous media, for example, OH • or O 2 •– , via the transfer of excited electrons to the metal centers, which then partake in the degradation of gemfibrozil ( Figure 6 b,c). 36 These species are well-known to facilitate oxidative chemistry. Moreover, oxy-radical generation is further enhanced by C 3 N 4 -catalyzed in situ formation of H 2 O 2 that assists in the oxidation of aromatic moieties.…”