The first report of covalently grafted semiconductors; n‐TiO 2 ‐P25 @ ECH @ WO 3 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 TiO 2 , is the most applicable semiconductor photocatalyst. However, the wide band‐gap of TiO 2 limits its application. A simple way to address this issue is to form heterojunction structures. RESULTS In the present work, n ‐TiO 2 ‐P25@ECH@WO 3 heterostructure photocatalyst was synthesized for the first time by a two‐step covalent grafting strategy. In this photocatalyst, two nano‐semiconductors, TiO 2 ‐P25 and WO 3 were anchored with epichlorohydrin (ECH) as the covalent linker. The properties of n ‐TiO 2 ‐P25@ECH@WO 3 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 ‐TiO 2 ‐P25@ECH@WO 3 oxidized benzyl alcohol to benzaldehyde with excellent selectivity and high yield. CONCLUSION In this study, n ‐TiO 2 ‐P25@ECH@WO 3 heterostructure photocatalyst was successfully synthesized and evaluated. ECH as the organic linker stably grafted two nano‐semiconductors, n ‐TiO 2 ‐P25 and n ‐WO 3 . The heterojunction that formed between n ‐TiO 2 and n ‐WO 3 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. © 2020 Society of Chemical Industry (SCI)