The first report of deep eutectic solvent (DES) nano-photocatalyst (n-TiO2-P25@TDI@DES(urea:ZnCl2)) and its application on selective oxidation of benzyl alcohols to benzaldehydes

BACKGROUND Deep eutectic solvents (DESs) are prepared by mixing solid organic precursors to form a liquid driven from strong hydrogen-bond interactions. The physical and chemical properties of these compounds have been widely investigated, and it has been shown that they are benign media for biotransformations, organicsynthesis, biodieselpreparation, and a sustainable media for nanoscale and functional materials. RESULTS This study is the first report on the synthesis of n-TiO2-P25@TDI@DES (urea: ZnCl2) with photo catalytic activity. This nano photocatalyst was obtained through covalent grafting of TiO2-P25 nanoparticles to an inexpensive and highly reactive linker (2,4-toluene diisocyanate). The presented nano photocatalyst has been employed as a covalently grafted Lewis acidic deep eutectic solvent to oxidize various primary benzyl alcohols to their corresponding carbonyl compounds by sodium nitrate as oxidant, under visible light exposure. CONCLUSION This highly efficient nanocatalyst was investigated by various characterization techniques including fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM with EDX), and elemental analysis. Owing to its enhanced catalytic activity, thermal stability, and environmentally friendly nature, the present method can be regarded as an attractive green chemistry approach. (c) 2020 Society of Chemical Industry (SCI)

Automated summary

This study presents the synthesis of a nano photocatalyst with photo catalytic activity for oxidizing benzyl alcohols to their corresponding carbonyl compounds. The nano photocatalyst was obtained through covalent grafting of TiO2-P25 nanoparticles to a highly reactive linker, showing enhanced catalytic activity and environmentally friendly nature. Characterization techniques including FT-IR, XRD, TGA, SEM with EDX, and elemental analysis were used to investigate the efficient nanocatalyst.