Solar hydrogen can now be produced efficiently without the scarce metal platinum

Good news! This could be a breakthrough! Photocatalysis without platinum  instead of electrolysis!

However, what are the effects of hydrogen power at large scale on the environment?

I have previously blogged here oft my critical opinion about hydrogen and water! And always remember the Hindenburg disaster of 1937!

"A research team led by Chalmers University of Technology, Sweden, have presented a new way to produce hydrogen gas without the scarce and expensive metal platinum. Using sunlight, water and tiny particles of electrically conductive plastic, the researchers show how the hydrogen can be produced efficiently, sustainably and at low cost. ...

In a new study, published in the scientific journal Advanced Materials, a research team led by Professor Ergang Wang at Chalmers, show how solar energy can be used to produce hydrogen gas efficiently – and completely without platinum.  ...

The key to the new approach lies in advanced materials design of the electrically conductive plastic used in the process. This type of plastic, known as conjugated polymers, absorbs light efficiently, but is typically less compatible with water.

By adjusting the material properties at the molecular level, the researchers made the material much more water compatible.

“We also developed a way to form the plastic into nanoparticles that can enhance the interactions with water and boost the light-to-hydrogen process. The improvement comes from more loosely packed, more hydrophilic polymer chains inside the particles” ..."

From the abstract:

"While the interest in hydrogen photocatalysis from organic semiconductors is rapidly growing, there is a necessity to achieve hydrogen production without platinum (Pt), considering its price, availability and toxicity.

In this work, this is demonstrated that high hydrogen evolution reaction (HER) efficiencies can be achieved without the use of Pt. A series of low-cost conjugated polymers are designed around the dibenzothiophene-S,S-sulfoxide (BTSO) unit, and self-assembled as nanoparticles in water via the nanoprecipitation technique.

This is highlighted that how side chain engineering, nanoparticle morphology and pH influence the hydrogen evolution rate.

Optoelectronic properties are improved through a Donor-Acceptor structure, resulting in an unprecedented hydrogen evolution reaction rate of 209 mmol g−1 h−1 in the absence of Pt.

A clear correlation between high efficiencies and number of BTSO units within the polymer backbone can be established. The design rules pioneer the design of future organic materials is presented for a cost-efficient and sustainable hydrogen photocatalysis."

Solar hydrogen can now be produced efficiently without the scarce metal platinum | Chalmers

Highly Efficient Platinum-Free Photocatalytic Hydrogen Evolution From Low-cost Conjugated Polymer Nanoparticles (open access, published in July 2025)

Credits: Wasserstoff aus Sonnenlicht: Gelingt so der große Durchbruch?

In the reactor at the chemistry laboratory at Chalmers, bubbles of hydrogen gas can be easily seen with the naked eye as they form – showing that photocatalysis is happening efficiently.

Fig. 1 Reported Hydrogen Evolution Reaction (HER) rates in the literature, updated in January 2025, and compared to the HER rate achieved in this work.

Fig. 2 a) Chemical structure of the polymers synthesized through a Suzuki-Miyaura cross-coupling polycondensation, highlighting in blue the electron accepting BTSO unit and in pink the electron donating thiophene unit.

b) Schematic representation of the nanoprecipitation mechanism, resulting in water-dispersed nanoparticles.

c) Absorption,

d) nanoparticle size distribution and e) hydrogen evolution of PFBTSO and PFgBTSO nanoparticles dispersed in water. Absorption spectra intensities were normalised at 405 nm. Photocatalytic experiments were performed using 0.25 mg of polymer nanoparticles in 10 mL of water, 0.1 M of ascorbic acid, no additional Pt cocatalyst and under 1 sun.