Map of 20 reactions that take place during vapor–solid phase photocatalytic dehydrogenation of ethanol on metal‐loaded TiO₂

Abstract

We report the map of 20 reactions that take place during vapor-phase photochemical dehydrogenation of ethanol on four metal-doped TiO 2 (M n /TiO 2 , M n = nanoparticles of Pd, Pt, Au, and Cu) under solar simulated light. The reactions are sensitively affected by the moisture amount and the nature of the carrier gas. To construct the above map, we also used CH 3 CHO, CH 3 CO 2 H, (C 2 H 5 O) 2 CHCH 3 , and CH 3 CO 2 C 2 H 5 , respectively, as an independent starting reagent. Amazingly, M n /TiO 2 not only serves as photocatalysts but also as thermocatalysts for various reactions that appear in the above map. The reaction is proposed to proceed by a radical mechanism in which photoinduced electron transfer from the valence band to the conduction band of TiO 2 is the initial step and the subsequent electron injection from organic reactants to the hole in the TiO 2 valence band. This report also features highly valuable unprecedented reactions, which bear great potential to be commercialized.

Surfactant-Free Mixed-Valence ReO3 Nanocubes for Solar Light Photocatalytic Applications

“…Nanostructured metal oxides such as TiO 2 , ZnO, and SnO 2 have been extensively studied as potential photocatalysts because of their high surface area, semiconducting properties, and cost-effectiveness. – Particularly TiO 2 nanoparticles are the most popular photocatalysts for the photodegradation of dyes and hydrogen generation by water splitting because of their photostability, nontoxicity, and high oxidative power. – However, the wide band gap of the intrinsic TiO 2 limits the enhancement of light harvesting capability over a wide range from UV to near-IR (NIR) to improve solar light or visible light photocatalytic efficiency. Hence, the light absorption range of TiO 2 nanoparticles has been tailored by synthesizing TiO 2 nanostructures or decorating their surfaces with some photosensitizers, dopants, and metal nanoparticles such as gold and silver which are the most known plasmonic materials sharing localized surface plasmon resonances (LSPRs) – This methodology is advantageous but consumes time and resources in the synthetic approach. In other words, the synthesis of most nanostructures has usually required capping agents such as surfactants and stabilizers.…”