Parameters Affecting Methylene Blue Dye Photodegradation by Carbon dots Prepared from Olive Pomace

• Published in: ChemistrySelect (Weinheim) Vol. 8; no. 14
• Main Authors: Sawalha, Shadi, Hamed, Rinad, Assali, Mohyeddin
• Format: Journal Article
• Language: English
• Published: 13-04-2023
• Subjects: degradation efficiency and rate; methylene blue dye; Olive pomace; photocatalyst dose; photodegradation
• ISSN: 2365-6549; 2365-6549
• DOI: 10.1002/slct.202300522

Olive pomace was used as a precursor in synthesizing CNDs through pyrolysis and oxidation. The photocatalytic activity of CNDs was evaluated for the degradation of methylene blue (M.B). dye under irradiation of a visible light source. The influence of various operational parameters such as the photocatalyst dose, solution pH, the initial concentration of M.B. dye, NaCl salt content, visible light source power, and distance were investigated and their effects on degradation rate and efficiency have been estimated. The photocatalytic mechanism and kinetic reaction were studied to find that ROS is responsible for causing a ‐pseudo‐first‐order photodegradation of the targeted dye. It was found that both rate and efficiency increased linearly with increasing the photocatalyst dose (CNDs) spiked into M.B solution, along with a maximum degradation first‐order rate of 0.061 min−1 obtained at pH=10.6 with an efficiency of 92 % after 120 minutes of light irradiation.
To photodegrade an organic dye such as methylene blue efficiently and rapidly, the operational conditions of the photocatalyst should be controlled. Synthesized carbon nanodots from olive pomace are an example of visible‐driven photocatalysts with higher efficiency and rate attained at basic pH, high light power, and lower initial pollutant concentration.