Solar energy-controlled shape selective synthesis of zinc oxide nanomaterials and its catalytic application in synthesis of glycerol carbonate

Highlights: • Solar energy assisted shape selective synthesis of ZnO nanomaterials. • Bioinspired use of aromatic amino acid to use solar energy. • Efficient synthesis of glycerol carbonate from glycerol and urea using calcined ZnO nanomaterials as a catalyst. In this study, we have synthesized shape selective zinc oxide (ZnO) nanoflower using solar energy and naturally accessible aromatic amino acids like tryptophan, tyrosine and phenylalanine as a photo capping agents. This synthesized material has been characterized by various characterization techniques such as XRD, FE-SEM, EDX, UV–Vis and FTIR. The ZnO nanoflower synthesized using solar energy and photo capping agents exhibited excellent catalytic activity after calcination for the synthesis of glycerol carbonate via urea glycerolysis as compared to the conventional process owing to its shape selective morphology. Further, high resolution XPS studies were performed to explore the valence states and effectiveness of surface engineering of the ZnO catalyst. Such a unique technique of ZnO nanoflowers synthesis represents a novel and environmentally benign route for synthesis of shape selective metal oxide nanoparticles as well as derived nanomaterial after calcination showed excellent activity and potential recyclability for the conversion of waste into valuable products. After calcination ZnO nanomaterials shows 67% yield in the synthesis of glycerol carbonate at 140°C in 4h, at the end a catalytic reaction mechanism was proposed.