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

Abstract

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. © 2020 Society of Chemical Industry (SCI)

ZIF-67/BiOCl Z-Scheme Heterojunction Photocatalyst for Photodegradation of Organic Dyes and Antibiotics

“…To date, due to the remarkable catalytic performance of semiconductor photocatalysts on organic pollutants, increasing attention has been given to the degradation of pollutants and environmental protection, and many studies have focused on semiconductor photocatalysts. However, traditional semiconductors such as ZnO and TiO 2 have wide band gaps and cannot make full use of solar energy, limiting their industrial applications . At present, Bi-based semiconductor materials have been continuously developed and a lot of scientists research the photocatalytic activity of various bismuth-based catalysts, such as g-C 3 N 4 /Na-BiVO 4 , Bi/Bi 2 WO 6 , Bi 2 MoO 6 , BiOBr, and other bismuth-based materials, , which present good photocatalytic degradation effects.…”

Glucose‐assisted preparation of n‐TiO2‐P25/Ag: An efficient and robust photocatalyst for enhancing visible‐light photo‐oxidation of benzyl alcohol

“…Nitrate reduces to nitrite, and nitrite individually cannot completely promote the reaction. [ 46,49 ]…”

“…Nitrate reduces to nitrite, and nitrite individually cannot completely promote the reaction. [46,49] On the other hand, the scavenging experiment was employed to prove that holes were major species for the oxidation of benzyl alcohol. Triethanolamine (TEOA) as a hole-scavenger was added to the reaction system to F I G U R E 1 2 Recycling of n-TiO 2 -P25/Ag F I G U R E 1 3 Possible S-scheme mechanism of n-TiO 2 -P25/Ag under blue LED light irradiation; *RP, reduction products remove holes.…”

“…Therefore, an optimum percentage of metals on TiO 2 facilitates the photocatalytic activity. [40] Considering the above points in mind, and within the framework of our continuing efforts for design and employ novel heterogeneous nanocatalysts [41][42][43][44][45] and their extension in photocatalytic reactions, [46][47][48][49] in this study, a new way is introduced for Ag deposition on the surface of nano TiO 2 -P25. Several processes have been explored to synthesize composite with Ag nanoparticles successfully.…”

Selective Oxidation of Benzyl Alcohol in the Aqueous Phase by TiO2‐Based Photocatalysts: A Review

“…A novel material, Co-TCPP@TiO 2 /WO 3 , was synthesized by anchoring cobalt(II)-meso-tetra-(4-carboxyphenyl)porphyrin (Co-TCPP) on TiO 2 /WO 3 and achieved a higher conversion of BnOH and visible-light adsorption [108,109]. Bitaraf and Amoozadeh [110] replaced Co-TCPP with epichlorohydrin (ECH) to link two nano-semiconductors, TiO 2 and WO 3 , under a blue light-emitting diode (LED) light source. The holes and electrons are separated effectively by the S-scheme in that study.…”