The first report of covalently grafted semiconductors; n-TiO2-P25@ECH@WO3 as a new, efficient, robust and visible-light-responsive photocatalyst

BACKGROUND Semiconductor nanomaterials have gained great attention as potential photocatalysts to promote environmentally benign organic reactions. Degussa P25, known as commercial TiO2, is the most applicable semiconductor photocatalyst. However, the wide band-gap of TiO2 limits its application. A simple way to address this issue is to form heterojunction structures. RESULTS In the present work, n-TiO2-P25@ECH@WO3 heterostructure photocatalyst was synthesized for the first time by a two-step covalent grafting strategy. In this photocatalyst, two nano-semiconductors, TiO2-P25 and WO3 were anchored with epichlorohydrin (ECH) as the covalent linker. The properties of n-TiO2-P25@ECH@WO3 were investigated through Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-Ray (EDX) and UV-visible/DRS techniques. Under blue LED light, n-TiO2-P25@ECH@WO3 oxidized benzyl alcohol to benzaldehyde with excellent selectivity and high yield. CONCLUSION In this study, n-TiO2-P25@ECH@WO3 heterostructure photocatalyst was successfully synthesized and evaluated. ECH as the organic linker stably grafted two nano-semiconductors, n-TiO2-P25 and n-WO3. The heterojunction that formed between n-TiO2 and n-WO3 significantly improved the light absorption performance with a considerable redshift to the visible region. Also, the photocatalyst showed an increased activity compared to individual semiconductors. (c) 2020 Society of Chemical Industry (SCI)

Automated summary

Semiconductor nanomaterials have attracted attention as potential photocatalysts for environmentally friendly organic reactions. A heterostructure photocatalyst, n-TiO2-P25@ECH@WO3, was successfully synthesized and evaluated in this study. The formation of a heterojunction between n-TiO2 and n-WO3 significantly improved light absorption performance, resulting in a considerable redshift to the visible region and increased activity compared to individual semiconductors.