An innovative green electrode architecture employing ON–OFF fluorescence signaling proposed to enhance the adsorption and controlled release of Ag and Pb ions to improve the reaction efficiency and minimize metal loss in the electro-click triazole named reaction

Abstract

Designing efficient electrocatalytic systems for electro-organic reactions is crucial, and in recent years numerous studies have focused on developing advanced electrode materials. However, many of these systems still face challenges such as limited reusability, leaching of metal nanoparticles into the environment, and increased production costs. To address these issues, an electrocatalytic system based on graphene oxide (GO) coated with ATPB@Ag or ATPB@Pb was developed. This system exhibits on/off fluorescence behavior, enabling controlled release of metal ions through pH adjustment. The catalyst was employed in the electro-organic reaction between ethynylbenzene 1(a) and NaN₃ 2(a) for the production of 5-phenyl-1H-1,2,3-triazole derivatives 3(a–l) under optimized conditions (5 mA current, 2 h reaction time, room temperature). The desired compounds were afforded in good to excellent yields (89–97%). The catalyst also demonstrated outstanding reusability, maintaining high efficiency over 12 consecutive cycles. After the reaction has reached completion, adjusting the pH allows the released metal ions to be re-captured by the catalyst, preventing the discharge of expensive and toxic heavy metals into the environment. This not only supports green chemistry principles but also significantly reduces production, maintenance, and operational costs. The structure and morphology of the synthesized catalyst were characterized utilizing pH analysis, FT-IR, SEM, EDS, BET, TGA, XPS, and CV techniques. Also, the synthesized 5-phenyl-1H-1,2,3-triazole derivatives 3(a–l) were confirmed by melting point measurements, ¹H NMR, ¹³C NMR, and CHN elemental analyses.