Green lithium niobate synthesized from Citrus latifolia extract: Development, characterization and photocatalytic activity for the rose bengal dye photodegradation with mechanistic insights using machine learning models

Green lithium niobate (gLiNbO 3 ) was developed via a green method using Citrus latifolia extract for the photodegradation of Rose Bengal (RB) dye via heterogeneous photocatalysis. In this regard, gLiNbO 3 exhibited a semi-amorphous structure with a low crystallinity index (±32%); Li-O and Nb-O bands; a high surface area of 259 m 2 g −1 ; a porous, lamellar, and foliated morphology; and a band gap energy of 3.1 eV. For the central composite rotatable design of RB photodegradation, the ideal condition was [gLiNbO 3 ] of 0.3 g L −1 , [RB] of 5.8 mg L −1 , pH ≈ 5, and T = 25 ± 2 °C with 81% RB photodegradation, demonstrating an apparent rate of the pseudo-first-order of k = 0.0085 min −1 . In the study of RB photodegradation, the process is governed by the Type I mechanism (Radical), in which photogenerated holes (h + ) and the hydroxyl radical ( • OH − ) are the primary oxidizing species. The reuse test demonstrated catalytic stability over five cycles, maintaining efficiency above 50%. Additionally, the use of machine learning allowed the capture of underlying chemical patterns related to the RB degradation mechanism, identifying intermediates that are not easily detectable. Therefore, gLiNbO 3 stands out as a promising platform for photocatalysis, with the scientific contribution being the validation of its photocatalytic functionality and the optimization of the RB mineralization process, paving the way for the development of catalysts for scalable environmental remediation.