Читать книгу Functionalized Nanomaterials for Catalytic Application - Группа авторов - Страница 22

The supply of graphene/graphene oxide–based functionalization resolves the constraints delivered by metal oxide PCs. Of late, attentions are focused on FNMs of graphene/graphene oxide–based semi-conductor materials as functionalized PC due to their smaller size with larger specific surface area supported by high electron (e⁻) conductivity and high adsorption capacity [141]. Advanced research work has been augmented on MO-G/GO FMNs photocatalytic systems [142] for oxidativereduction of pollutants (BG) [143] and (MB) [144]. The unstable and aggregation tendency of the NMs are retarded by the advantages raised due to FNMs.

In one of their studies, researchers Rao, G. et al. synthesized TiO₂-NW/Fe₂O₃-NP/GO FNM sheets by colloid-blending scheme, where the material was found to have 93% efficacy in getting rid of humic acid from water photocatalytically at a pH 6. TiO₂ furnished h⁺ required for ^·OH and GO the e⁻ needed for ^·O²⁻ needed for the activity [145]. GO/MCU-C₃N₄/PVDF materials synthesized by vacuumized self-assembly and cross-linking process had exceptional self-cleaning property, which was proven fit for separating oil-in-water colloidal emulsions. Photocatalytic degrading capabilities were attributed to the e⁻ transferences from CB (1.61 eV) to VB (1.18 eV), with π-π* transition giving h⁺ in VB. h⁺, ^·O²⁻, and ^·OH were controllers in the reaction for eradicating oil-foulants as observed by the researchers Shi, Y. et al. [146].

Scientific workers Gnanamoorthy, G. et al. synthesized AF-Bi₂Sn₂O₇/rGO (AF-amine functionalized) FNMs for photocatalytic degradation of organic dye MB in the visible region was 75% (20 min). Bandgap between pure (2.6 eV) and FNMs (1.6 eV) decreased. VB with h⁺ and CB with e⁻ that favored the reaction were supported by the formation of radicals ^·O²⁻ and ^·OH. Stability and reusability of FNMs were persistent up to four cycles [147]. In one of their methods, the authors Liu, H. et al. used FNMs of Bi₂Sn₂O₇/RGO to reduce and degrade Rh B and phenol photocatalytically in the bright visible region (420 nm) and noticed that the degrading efficiencies were 95.8% (125 min) and 81.1% (200 min) for Rh B and phenol, respectively. On embedding RGO on Bi₂Sn₂O₇ (pure), they observed that there was a decrease in the bandgap from 2.48 eV (pure) to 1.85 eV FNM which served well for degrading the contaminant, where the active radicals involved for the reaction was h⁺ and ^·OH [148].