(Invited) Hydrogen and Methylcyclohexane Production By Solar Water Splitting Using Photoelectrochemical Cells

Monday, 2 October 2017: 08:40
National Harbor 6 (Gaylord National Resort and Convention Center)
T. Minegishi (The University of Tokyo, JST/PRESTO) and K. Domen (The University of Tokyo)
Production of energy carriers through the solar water splitting have been attracted huge attentions as the key technology to construct a sustainable energy society. Hydrogen is the promising candidate for energy carrier because of its simple production through water splitting and utilization in many devices including fuel cells. On the other hand, Methylcyclohexane (MCH) is the promising hydrogen carrier because of its high hydrogen content per volume and usability of existing infrastructures. Herein, we investigated photoelectrochemical (PEC) hydrogen production from water and PEC MCH production through hydrogenation of toluen in existence of water as a hydrogen source.

For efficient PEC solar hydrogen and MCH production, utilization of photocatalytic materials with narrow bandgap energy is indispensable. The combination of a photoanode and a photocathode can relax the requirements for the photoelectrodes through the accumulation of driving forces.

The solid solution of ZnSe and Cu(In, Ga)Se2, ZnSex:CIGS1-x, shows relatively large cathodic photocurrent with high onset potential under simulated sunlight.1,2) The PEC cell composed of surface modified ZnSe-CIGS photocathode and BiVO4 photoanode could drive water splitting reaction with a solar-to-hydrogen conversion efficiency of hither than 1%. The PEC cell consisting of ZnSe-CIGS based membrane-photoelectrode assembly (MPA) and a BiVO4 photoanode also showed spontaneous conversion of toluene to MCH with water as a hydrogen source. In the presentation, the effects of surface modifications on durability and performance of the PEC cell for direct production of hydrogen and MCH will be discussed. 

1) H. Kaneko, T. Minegishi, M. Nakabayashi, N. Shibata, Y. Kuang, T. Yamada, K. Domen, Adv. Func. Mater., 2016, 26, 4570-4577.

2) H. Kaneko, T. Minegishi, M. Nakabayashi, N. Shibata, K. Domen, Angew. Chem. Int. Ed., 2016, 55, 15329-15333.