Particulate photocatalyst sheets for efficient and scalable solar hydrogen production via water splitting

7^th Annual Congress on Materials Research and Technology

February 20-21, 2017 Berlin, Germany

Kazunari Domen

University of Tokyo, Japan

Posters & Accepted Abstracts: J Material Sci Eng

Abstract :

Photocatalytic water splitting driven by solar energy has been studied extensively as a means of renewable hydrogen production on a large scale. A solar-to-hydrogen energy conversion efficiency (STH) of 5% or higher is considered to be necessary for practical operation of photocatalytic solar hydrogen production. To attain such a high STH at reasonable quantum efficiencies, it is necessary to activate and stabilize narrow band gap semiconductor photo-catalysts. Scalability of the system is also an important concern. In this regard, development of particulate photocatalysts that are active in the water splitting reaction without an external power supply is important. Recently, the author�s group has studied photocatalyst sheets based on particulate hydrogen evolution photocatalyst (HEP) and oxygen evolution photocatalyst (OEP) embedded into conductive layer by particle transfer for efficient and scalable water splitting. The STH of pure water splitting using photocatalyst sheets consisting of La- and Rh-codoped SrTiO3 (SrTiO3:La,Rh) as a HEP and Mo-doped BiVO4 (BiVO4:Mo) exceeds 1.1% superior to those for corresponding powder suspension systems. The high activity of the photocatalyst sheet is due to the underlying conductive layer allowing for the efficient electron transfer between HEP and OEP particles. In addition, evolution of hydrogen and oxygen in close proximity allows preventing generation of pH gradient during the water splitting reaction. However, the absorption edge wavelengths of SrTiO3:La,Rh and BiVO4:Mo are 540 nm at most. It is still important to develop photocatalysts with longer absorption edge wavelengths. In my talk, recent progress and future challenges in photocatalytic water splitting and system development will be presented.

Biography :

Email: domen@chemsys.t.u-tokyo.ac.jp