Japan Realized Producing Hydrogen by Tungsten Oxide Electrode under Room Temperature through Visible Light

A research group lead by Professor of Japan Kyushu Municipal University recently developed a new method which is to use visible light under room temperature, complete the transfer of CH4 into C2H6 and H2 only in one step.

The traditional CH4 transfer method needs several steps and will consume a lot of energy, researchers have been doing efforts to developing a process to transfer it into useable chemicals. Usually under high temperature, the stable C-H key will be activated on hot catalyst. Although photocatalyst can transfer CH4 into methyl radical under room temperature, but it need high energy light such as ultra-violet. It also has low efficiency in the absorbed photon. In the latest study, the research group developed photo electric chemical reaction process used in activating gaseous molecules, transfer CH4 into C2H6 and H2 under low temperature by visible light. When using tungsten oxide electrode, illuminate under blue visible light and conduct CH4 homogeneous coupling reaction, 50% will generate C2H6. By adding electric field, recombination of photo activated electron and hole will be exhibited. Compared to the traditional photocatalytic method, the quantum efficiency is promoted. This is the first time using visible light to generate hydrogen under room temperature.

tungsten oxide photo

The new method is expected to use abundant resource CH4 to generate H2 and other chemical products to create new fuel chemical industry.

Tungsten oxide is a kind of new semiconductor material, it is also one of the semiconductor metal oxide which is easy to realize quantum size effective. It has property of electrochromism, absorption and catalyst. It has been widely applied in fuel cell, chemical conductor, photo electric device. Tungsten oxide electrode has perfect electrochemical property, it has high coulombic efficiency and have stability of circulation and structure.