Electrochemical oxidation degradation of Rhodamine B dye on boron-doped diamond electrode: Input mode of power attenuation

Electrocatalytic Degradation of Rhodamine B on the Sb-Doped SnO2/Ti Electrode in Alkaline Medium

“…The p-type electron orbital of N is bound to the benzene ring, making the ethyl group at the N-position easily attacked due to electron delocalization. Therefore, hydroxyl radicals produced in the electrocatalytic oxidation first cause the N-de-ethylation of RhB to form product I (C 26 H 27 N 2 O 3 + , m / z = 415), product II (C 24 H 23 N 2 O 3 + , m / z = 387), product III (C 20 H 15 N 2 O 3 + , m / z = 331). , Subsequently, hydroxyl radicals attack the N-de-ethylation products to induce denitrification and decarboxylation reactions, thus forming product IV (C 20 H 15 NO 3 , m / z = 318) and product V (C 19 H 15 NO, m / z = 274) . Then, hydroxyl radicals continue to attack the structural center of RhB, leading to the destruction of the conjugated xanthene structure, e.g., the cleavage and ring-opening of product V form product VI (C 13 H 9 O, m / z = 181) and small molecule organic acids, such as product VII (C 7 H 6 O 4 , m / z = 154) and product VIII (C 7 H 6 O 2 , m / z = 122) …”

“…Therefore, hydroxyl radicals produced in the electrocatalytic oxidation first cause the N-de-ethylation of RhB to form product I ( + , m/z = 331). 14,56 Subsequently, hydroxyl radicals attack the N-deethylation products to induce denitrification and decarboxylation reactions, thus forming product IV (C 20 H 15 NO 3 , m/z = 318) and product V (C 19 H 15 NO, m/z = 274). 57 Then, hydroxyl radicals continue to attack the structural center of RhB, leading to the destruction of the conjugated xanthene structure, e.g., the cleavage and ring-opening of product V form product VI (C 13 H 9 O, m/z = 181) and small molecule organic 56 Combining the analysis of the degradation pathways and UV−vis absorption spectra, the degradation mechanism of RhB using the Sb-doped SnO 2 /Ti electrode was speculated, and the schematic illustration is shown in Figure 7.…”

“…As a typical organic dye, Rhodamine B (RhB) can color the water even at very low concentrations (approximately 1.0 mg·L –1 ), thus hindering the photosynthetic processes of aquatic organisms . Moreover, RhB has been found to have potential carcinogenicity, teratogenicity, and mutagenicity, and is difficult to degrade in the natural environment. − In recent years, many studies have used RhB as the representative pollutant to investigate the treatment of organic dyes in wastewater and various anodes have been developed by boron-doped diamond (BDD), dimensionally stable anodes (DSA), , PbO 2 , − SnO 2 , ,− and several new materials. − In these studies, the effectiveness of electro-oxidation for the degradation of RhB has been proven, but it should be noted that these electrocatalytic oxidation processes usually run under neutral or weakly acidic conditions and the degradation performance of RhB in alkaline medium is not satisfactory. Liu et al reported that the removal efficiency of RhB was only 10% at the initial pH of 9, which is significantly lower than 96% in acid medium (pH 3) using the carbon nanotubes (CNTs)/agarose (AG) membrane on the ITO (indium tin oxide) electrode.…”

Step-by-step guide for electrochemical generation of highly oxidizing reactive species on BDD for beginners

“…Once BDD is electrochemically characterized to “micro-scale,” the next step is the search for the “ideal” parameters to carry out electrochemical oxidation with the greatest efficiency, driven mainly by HORS, which will be discussed in depth later. AEO is a complex process involving the balance of several variables that must be carefully controlled in practice ( Ganiyu et al, 2021 ; Bany Abdelnabi et al, 2022 ; Lee et al, 2022 ; Xu et al, 2023a ; Zheng, 2023 ). In this section, we will focus mainly on the potential and/or current density to be applied to the system and how the electrochemical test should be carried out to find it.…”

Biomimetic seaweed absorbable membrane for dye adsorption in wastewater treatment

“…12 To date, scientists have explored many methods to remove dyes from wastewater. 13 The common methods include photochemical degradation, 14 electrochemical degradation, 15 adsorption, and oxidation. 16 Among them, the adsorption method has become one of the most effective methods to remove dyes from wastewater because of its simple design and operation and high economic applicability.…”