Inducing state transitions in algae for efficient photosynthetic hydrogen production

The growing energy crisis and environmental pollution have driven the need for green energy solutions. Biological photosynthetic hydrogen production holds great promise but is hindered by low hydrogen production efficiency. This study proposed a dark adaptation strategy to enhance algal hydrogen production, achieving a high average hydrogen production rate of 19.42 μmol H₂ (mg chlorophyll)⁻¹h⁻¹. Dark adaptation activates hydrogenases and shifts the light-harvesting complex II from PS II to PS I, enhancing hydrogen production. By applying dark adaptation every 25 days, continuous hydrogen generation was sustained for over 150 days, yielding 3.81 L of H₂ in a 50 mL photoreactor. This efficient and scalable method advances algae-based green energy, promoting its commercial application and accelerating the transition to sustainable energy.