Photocatalytic synthesis of chromeno[4,3-b]chromenes, serving as potential drugs in oral cavity and dentistry mediated by TiO₂/Ag₂WO₄

Abstract This research focused on a newly developed heterojunction nanocomposite, TiO 2 /Ag 2 WO 4 , which combines titanium dioxide (TiO 2 ) and silver tungstate(VI) (TiO 2 /Ag 2 WO 4 ) to enhance the photocatalytic performance. The TiO 2 /Ag 2 WO 4 photocatalyst was characterized using FT-IR, XRD, DRS, PL, SEM, EDS, and XPS. TiO 2 /Ag 2 WO 4 proved to be an effective nanophotocatalyst for synthesizing chromeno[4,3-b]chromene derivatives, which exhibit potential antibacterial and antifungal properties relevant to oral health issues like dental caries and periodontal disease. TiO 2 can absorb light to generate electrons and holes when exposed to direct light; however, combining it with Ag 2 WO 4 enhances its photocatalytic activity. The study also examined the effects of various factors such as the amount of photocatalyst, reaction time, temperature, solvent choice, and the reusability of the nanocomposite. The best reaction condition involves 1 mmol of dimedone, benzaldehyde, and 4-hydroxycoumarin in the presence of 15 mg TiO 2 /Ag 2 WO 4 in 3 ml ethanol under irradiation of a green laser at room temperature for 60 min. Findings of this investigation show that TiO 2 /Ag 2 WO 4 heterojunction is one of the best among the similar introduced counterparts in photocatalytic synthesis of chromeno[4,3-b]chromene derivatives.