UV-Based Advanced Oxidation Processes of Remazol Brilliant Blue R Dye Catalyzed by Carbon Dots

Inês M F Cardoso; Rita M F Cardoso; Luís Pinto da Silva; Joaquim C G Esteves da Silva

doi:10.3390/nano12122116

UV-Based Advanced Oxidation Processes of Remazol Brilliant Blue R Dye Catalyzed by Carbon Dots

Nanomaterials (Basel). 2022 Jun 20;12(12):2116. doi: 10.3390/nano12122116.

Authors

Inês M F Cardoso¹, Rita M F Cardoso¹, Luís Pinto da Silva¹, Joaquim C G Esteves da Silva¹

Affiliation

¹ Chemistry Research Unit (CIQUP), Institute of Molecular Sciences (IMS)-DGAOT, Faculty of Sciences of University of Porto (FCUP), Rua do Campo Alegre s/n, 4169-007 Porto, Portugal.

Abstract

UV-based advanced oxidation processes (AOPs) (UV/H₂O₂ and UV/S₂O₈^2-) with a titanium(IV)-doped carbon dot, TiP-CD, as a catalyst were developed for the decomposition of Remazol Brilliant Blue R (Reactive Blue 19), an anthraquinone textile dye (at T = 25 °C and pH = 7). The Ti-CD, with marked catalytic UV properties, was successfully synthesized by the one-pot hydrothermal procedure, using L-cysteine as carbon precursor, ethylenediamine as nitrogen source, PEG (polyethylene glycol) as a capping agent, and titanium(IV) isopropoxide (precursor of TiO₂ doping). Contrary to azo dyes (methyl orange, orange II sodium salt, and reactive black 5), which achieved complete degradation in a time interval less than 30 min in the developed AOP systems (UV/H₂O₂, UV/S₂O₈^2-, and UV/TiO₂), the RBB-R showed relatively low degradation rates and low discoloration rate constants. In the presence of the catalyzer, the reaction rate significantly increased, and the pseudo-first-order rate constants for the RBB-R discoloration were UV/3.0 mM H₂O₂/TIP-CD-0.0330 min^-1 and UV/1.02 mM S₂O₈^2-/TIP-CD-0.0345 min^-1.

Keywords: Remazol Brilliant Blue R; UV based AOP; carbon dots; nanomaterials; reactive blue 19; textile dyes.

Grants and funding

The Portuguese “Fundação para a Ciência e Tecnologia (FCT)” is acknowledged for funding the R&D unit CIQUP (Project UIDB/00081/2020) and the Associated Laboratory IMS (LA/P/0056/2020).