Synergistic effects of covalently coupled eosin-Y with Ben-graphitic carbon nitride framework for improved photocatalytic activity in solar light-driven Biginelli product generation and NADH regeneration.

Elevated global pollution level is the prime reason that contributes to the onset of various harmful health diseases. The products of Biginelli reaction are enormously used in the pharmaceutical industry as they have antiviral, antibacterial, and calcium channel modulation abilities. This work reports a novel eosin Y sensitized boron graphitic carbon nitride (EY-B_en-g-C₃N₄) as a photocatalyst that efficiently produced 3,4-dihydropyrimidine-2-(1H)-one by the Biginelli reaction of benzaldehyde, urea, and methyl acetoacetate. The photocatalyst EY-B_en-g-C₃N₄ showed a successful generation of 3,4-dihydropyrimidine-2-(1H)-one (Biginelli product) in good yield via photocatalysis which is an eco-friendly method and has facile operational process. In addition to the production of Biginelli products, the photocatalyst also showed a remarkable NADH regeneration of 81.18%. The incorporation of g-C₃N₄ with boron helps increase the surface area and the incorporation of eosin Y which is an inexpensive and non-toxic dye, and in B_en-g-C₃N₄, enhanced the light-harvesting capacity of the photocatalyst. The production of 3,4-dihydropyrimidine-2-(1H)-one and NADH by the EY-B_en-g-C₃N₄ photocatalyst is attributed to the requisite band gap, high molar absorbance, low rate of charge recombination, and increased capacity of the photocatalyst to harvest solar light energy.