Sonocatalytic performance of ZnO/graphene/TiO2 nanocomposite for degradation of dye pollutants (methylene blue, texbrite BAC-L, texbrite BBU-L and texbrite NFW-L) under ultrasonic irradiation

Photocatalytic decontamination of phenol and petrochemical wastewater through ZnO/TiO2 decorated on reduced graphene oxide nanocomposite: influential operating factors, mechanism, and electrical energy consumption

“…Combination of wide bandgap semiconductors with narrow bandgap semiconductors and formation of type I heterojunctions can enhance the photocatalytic activity of titania. [17][18][19][20][21][22][23][24][25] The composite of TiO 2 and ZnO has shown to have a higher photocatalytic activity than pristine TiO 2 and/or ZnO because of type II hetero-junction formation which inhibits the e/h recombination rate. Furthermore, the heterogeneous structure formation by two semiconductors extends the photo response of composites to visible light area.…”

“…Many heterogeneous nanostructure photocatalysts coupled with graphene nanosheets have been synthesized and developed in recent years. 17,19,26,[31][32][33][34] Photocatalytic process efficiency is signicantly affected by electron-hole recombination rate which could be controlled by various parameters such as interfacial properties, electronic properties, chemical composition, and physical dimension. 23 Various statements have been suggested about the characteristics of graphene in hetero-structure nanocomposites which included graphene nanosheets in their frameworks: (I) formation of Zn-O-C, Zn-C, and Ti-O-C bonds by graphene defect states improves the solar or visible light adsorption capacity of catalysts; (II) graphene can accept or donate electrons due to its high electron mobility in order to reduce the e/h recombination rate of ZnO/ TiO 2 nanocomposite, thus prolonging the life-time of excited electrons during the reaction; (III) graphene enhances the adsorption capacity of nanocomposites and creates more reactive sites for sorption of target contaminants because of its high BET specic surface area.…”

“…Therefore, GO nanosheets are commonly used in the synthesis of photocatalytic nanocomposites. Thus, we expected that the introduction of rGO in the TiO 2 17 Malekshoar et al used TiO 2 /graphene, ZnO/graphene and their physical mixture for degradation of phenol with sun light irradiation. 26 Liu et al synthesized ZnO/TiO 2 /rGo nanocomposite via microwave-assisted method and evaluated its photocatalytic performance by reduction of Cr(VI).…”

A Facile Synthesis of La2O3/GO Nanocomposites in N,N-Dimethylformamide with High Dye Degradation Efficiency

“…As shown in Figures 4(a), 4(b), and 4(c), the absorbance of MB, Rh, and MO would be decreased in presence of La 2 O 3 /GO nanocomposites under ultrasound irradiation for 15 min. The decomposition may be due to the reaction of dye molecules with hydroxyl radical which is formed under the ultrasonic irradiation in the presence of La 2 O 3 /GO nanocomposites [16]. And the degradation efficiency for MB, Rh, and MO was shown in Figure 4(d).…”

Facile synthesis of mesoporous titanium dioxide doped by Ag-coated graphene with enhanced visible-light photocatalytic performance for methylene blue degradation

“…[15][16][17] Thus, the addition of GR to bulk TiO 2 has been observed to improve activity under visible-light irradiation for the degradation of dodecyl benzenesulfonate, 18 methylene blue (MB), 19 Eosin blue dye, 20 and texbrite pollutants. 21 However, little effort has seemingly been made to combine Ag, GR, and MT. Herein, a visible-light-driven MT catalyst is proposed, considering the synergistic effects of the GR support and Ag doping on the structure and photocatalytic activity of MT.…”