Enhancing Photocatalytic Degradation of Methylene Blue Using ZnO/Carbon Dots Nanocomposite Derived From Coffee Grounds

Abstract

Fujishima and Honda discovered a water splitting phenomenon in their experiment on the electrochemical photolysis of water used semiconductor electrode [1]. During their experiment, Fujishima and Honda discovered a photocatalytic activity of TiO 2 and began testing this semiconductor as a photocatalyst. Since then the development of the photocatalysis mechanism involving the semiconductor material as a photocatalyst to decompose the organic dyes began to increase very

Utilizing Cymbopogon Proximus Grass Extract for Green Synthesis of Zinc Oxide Nanorod Needles in Dye Degradation Studies

“…The lower degradation efficiency of organic compounds under visible light, as compared to UV light, can be attributed to the relatively larger bandgap energy of ZnO-NRNs [ 60 , 61 , 62 , 63 ]. The larger bandgap energy necessitates higher-energy photons, which are predominantly present in the UV spectrum, to initiate photocatalytic reactions.…”

“…An electron-hole pair (eCB + hVB+) is created when solar radiation hits ZnO-NRNs. This process involves the transfer of electrons from the valence band to the conduction band, as follows: The lower degradation efficiency of organic compounds under visible light, as compared to UV light, can be attributed to the relatively larger bandgap energy of ZnO-NRNs [60][61][62][63]. The larger bandgap energy necessitates higher-energy photons, which are predominantly present in the UV spectrum, to initiate photocatalytic reactions.…”

Green synthesis of zinc oxide nanoparticles toward highly efficient photocatalysis and antibacterial application

“…ZnO has a rather high bandgap energy; therefore, the degradation efficiency of organic substances under visible light is not as high as that under UV light. Maddu et al [ 34 ] studied the preparation of ZnO NPs with a size of 30 nm. The degradation efficiency of MB (5 mg/L) after 150 min of irradiation by visible and UV light was 40 and 80%, respectively, while synthesized ZnO NPs in this study can degrade more than 90% of MB (10 mg/L) under UV light after 150 min.…”

Photocatalytic Performance of TiO₂-ZnAl LDH Based Materials: Kinetics and Neural Networks Approach

“…Heterogeneous photocatalytic oxidation that involves free-radical reactions initiated by light irradiation of the photocatalysts' surface is one of the promising purification methods [4,5]. These photocatalytic semiconductors can operate under specific light spectrum range and their efficiency depend predominately on the electron-hole pairs' mobility and on the accessibility of active sites, but is additionally influenced by other numerous factors [6,7].…”