Hydrogen is an abundant chemical element made of one electron and one proton, and in standard conditions it exists in molecular form as H2 gas. Hydrogen is a colorless, odorless and highly combustible nonmetal that is often stored in high-pressure tanks in its gas or liquid form.
Green hydrogen is formed through electrolysis, which uses electricity from renewable sources such as wind or solar power to split water into hydrogen and oxygen. Since the source is from renewable energy, the fuel is truly emission-free and clean, making it “green.”

“The combination of coatings and cocatalysts makes it possible for electrons and holes to separately transport through the coating by design with minimum recombination,” Hu said. “That makes this kind of particle-based solar fuel generators work.”