Enhancing photodegradation of methylene blue and reusability using CoO/ZnO composite nanoparticles

A Review of Synthesis Methods, Modifications, and Mechanisms of ZnO/TiO2-Based Photocatalysts for Photodegradation of Contaminants

“…Metal oxides from groups II–VI are considered as n-type semiconductors, which are active in UV range of light irradiation, and one main reason for their restricted usability as photocatalysts is fast recombination of photoexcited species. Doping with other metal oxides with lower band gaps and or introducing metal oxides as photoexcited trapping agents improves the base semiconductor quantum efficiency. − A literature survey shows that some transition metals as d-type and p-type doping groups on the TiO 2 and ZnO surface are Cr 2 O 3 , SnO, MnO 2 , , FeO, CoO, NiO, Cu 2 O, and CuO . Baniamerian et al , disclosed the application of a Fe 2 O 3 /TiO 2 photocatalyst synthesized by ultrasonic co-precipitation method and evaluated MB photodegradation under visible light radiation.…”

“…Doping with other metal oxides with lower band gaps and or introducing metal oxides as photoexcited trapping agents improves the base semiconductor quantum efficiency. 172 − 174 A literature survey shows that some transition metals as d-type and p-type doping groups on the TiO 2 and ZnO surface are Cr 2 O 3 , 175 SnO, 176 MnO 2 , 177 , 178 FeO, 179 CoO, 180 NiO, 181 Cu 2 O, 182 and CuO. 183 Baniamerian et al 184 , 185 disclosed the application of a Fe 2 O 3 /TiO 2 photocatalyst synthesized by ultrasonic co-precipitation method and evaluated MB photodegradation under visible light radiation.…”

Microwave-assisted synthesis of ZnO structures for effective degradation of methylene blue dye under solar light illumination

“…15,16 Zinc oxide stands out as a distinctive n-type semiconductor; although, the quick recombination rate of photogenerated electron–hole pairs, as well as its wide bandgap of 3.3 eV 17 , hinder its extensive application as a photocatalyst. To date, extensive research has been conducted on various methodologies for the synthesis of various ZnO structures, including microwave-solvothermal, 18 hydrothermal, 19 precipitation, 20 biogenic, 21 sol–gel, 22 and electrodeposition 23 methods. Although many of these techniques have not been extensively employed on a large scale, the microwave-assisted synthesis of ZnO may gain widespread popularity due to its simplicity and cost-effectiveness.…”

Zinc Oxide Films Fabricated via Sol-Gel Method and Dip-Coating Technique–Effect of Sol Aging on Optical Properties, Morphology and Photocatalytic Activity

“…The latest literature reports indicate a wide interest in modified ZnO materials due to the possibility of shifting the spectral range of absorbed electromagnetic radiation in the presence of a certain photocatalyst. This is achieved by doping ZnO with metals or non-metals [31], or by producing hybrid structures with other metal oxides [32] or nanocomposites [33][34][35]. Excellent photocatalytic and antibacterial activity was also observed for hybrid systems of zinc oxide nanoparticles with reduced graphene oxide and gold nanoparticles [36].…”