Background
Dominant methods to make hydrogen require fossil fuels such as natural gas. Renewable approaches to hydrogen production have employed expensive precious metal catalysts like platinum which are too costly to be commercially viable and/or chromophores which often require non-aqueous solutions and exhibit short decomposition lifetimes.
Technology Overview
Researchers at the University of Rochester have developed a system that uses inexpensive catalysts and nanoparticles to make hydrogen from water and sunlight with the same efficiency as precious metal catalysts. In its most general sense, as described in patents, this is done by using a nanoparticle photosensitizer along with a metal complex catalyst and an electron source in an aqueous solution. For example, the photosensitizer might be CdSe nanoparticles, with a water-soluble nickel catalyst and ascorbic acid as the electron source. Other nanoparticles, metal complex catalysts, and electron sources can be envisioned.
The nanoparticle photosensitizer efficiently absorbs incident light within the absorption band of the quantum dot. The excited quantum dot causes an intermolecular charge transfer by reducing the catalyst using a sacrificial doner from the electron source. The reduced catalyst then forms H2 from the aqueous solution.
Benefits
This hydrogen production method exhibits excellent longevity and utilizes low-cost catalysts, enabling cost-effective chemistries to be employed for solar hydrogen production.
Applications
Hydrogen production