A new method for converting solar energy into easy-to-use hydrogen with high conversion efficiency will be developed.

In recent years, wind power generation and solar power generation have been attracting attention as environmentally friendly renewable energy, but there is a problem that converting energy into electric form has limited uses and cannot be used in places where the power grid is not maintained. I have. Therefore, a research team at Umeå University in Sweden has developed 'a method for efficiently converting solar energy into easy-to-use hydrogen using materials that are abundant on the earth.'

Solar-Driven Water Splitting at 13.8% Solar-to-Hydrogen Efficiency by an Earth-Abundant Electrolyzer | ACS Sustainable Chemistry & Engineering

https://pubs.acs.org/doi/10.1021/acssuschemeng.1c03565

In recent years, the momentum to reduce carbon dioxide emissions has increased worldwide in various fields, and power generation using renewable energy such as solar power can be said to be the centerpiece. However, less than 20% of the world's energy consumption is consumed directly in the form of electricity, and in many areas the power grid is not well-developed, so all energy used around the world will be replaced by solar power generation. You can't do that.

A research team at Umeo University said that if water is electrolyzed with solar energy and converted into hydrogen fuel , it can be used directly as fuel or finally converted into electricity as a fuel cell, so it depends on fossil fuels. It claims that converting renewable energy to hydrogen fuel is an effective way to reduce it.

Therefore, the research team developed a device that converts sunlight into electricity and electrolyzes water to produce hydrogen using perovskite solar cells that can be made on thin glass or plastic substrates using printing technology. ..

The electrodes used to electrolyze water are carbon paper made of carbon fibers with a diameter of 10 micrometers to 20 micrometers coated with a thin film of carbon nanotubes formed by chemical vapor deposition (chemical vapor deposition). It was made by decorating it with a metal catalyst. It is stated that three types of metals, iron, nickel, and molybdenum, which are abundant on the earth, were selected in consideration of sustainability and the promotion of electrolysis reaction as the metal used for the catalyst.

When the research team actually put into operation an electrolyzer developed by a new method, it was confirmed that solar energy was converted to hydrogen with a high efficiency of 13.8%. The energy conversion efficiency of a general photovoltaic power generation panel is said to be about 20%, and it may seem that this method is not high if you look only at the conversion efficiency, but hydrogen that can be used for various purposes instead of electricity. It is important that it can be used as fuel. Hydrogen fuel has a high energy density per weight and is used for cars, etc., and it is said that it can be used for industrial purposes such as the production of carbon-free steel and ammonia.

The research team emphasizes that the electrolyzer developed this time uses perovskite solar cells, which can be manufactured at a lower cost than conventional solar cells, and that electrodes are made using materials that are abundant on the earth.