Designing Photocatalysts for Hydrogen Evolution: Are Complex Preparation Strategies Necessary to Produce Active Catalysts?. Issue 18 (10th August 2015)

• Record Type: Journal Article
• Authors: Grewe, Tobias; Tüysüz, Harun
• Is Part Of: ChemSusChem. Volume 8:Issue 18(2015:Sep.)
• Page Start: 3084
• Page End: 3091
• Publication Date: 2015-08-10
• Subjects: Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.201500774
• Languages: English
• ISSNs: 1864-5631

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>A facile synthetic route for the preparation of highly active photocatalysts was developed. The protocol involves the preparation of a photocatalyst through the direct injection of metal alkoxide precursors into solutions in a photoreactor. As a proof of concept, a tantalum oxide based photocatalyst was chosen as a model system. Tantalum ethoxide [Ta(OEt)<sub>5</sub>] was injected rapidly into a photoreactor filled with a water/methanol mixture, and a TaO<sub><italic>x</italic></sub>(OH)<sub><italic>y</italic></sub> composite formed and was able to produce hydrogen under light illumination. Compared to commercial and mesostructured Ta<sub>2</sub>O<sub>5</sub> and NaTaO<sub>3</sub> materials, TaO<sub><italic>x</italic></sub>(OH)<sub><italic>y</italic></sub> produced by direct injection shows superior hydrogen production activity. Notably, the samples prepared by direct injection are amorphous; however, their photocatalytic performance is much higher than those of their crystalline equivalents. If Ta(OEt)<sub>5</sub> was dispersed in methanol before injection, an amorphous framework with higher surface area and larger pore volume was formed, and the hydrogen production rate increased further. The addition of a sodium precursor during the injection further boosted the photocatalytic activity. Furthermore, this concept has also been applied to a titanium‐based photocatalyst, and a much better hydrogen production rate has been obtained in comparison with that of commercial TiO<sub>2</sub> (P25‐Degussa); therefore, the direct‐injection synthesis is a flexible method that opens the door to the facile preparation of highly active nanostructured photocatalysts for hydrogen production.</p> </abstract>