China has demonstrated the world's first direct solar-driven seawater splitting device — a compact photocatalytic system that produces green hydrogen from seawater using only sunlight, without conventional electrolysis equipment, membrane separators, or external power supplies.
Researchers at Nanjing University developed a cobalt phosphide co-catalyst loaded onto carbon nitride semiconductor sheets, immersed directly in seawater and illuminated by concentrated sunlight. The catalyst absorbs photons energetic enough to split water molecules, releasing hydrogen and oxygen without any external electricity. Seawater salt and minerals actually enhanced catalytic activity by 15 percent compared to fresh water, eliminating the costly desalination step required by conventional marine electrolysis systems.
In a 1,000-hour continuous operation test under outdoor natural sunlight, the photocatalytic array produced hydrogen at 9.2 percent solar-to-hydrogen efficiency — approaching the 10 percent threshold considered commercially relevant. Scaling calculations suggest a 1-square-kilometer photocatalytic seawater array could produce 4,500 tonnes of hydrogen annually using only sunlight and ocean water as inputs with zero infrastructure cost for fuel supply.
Source: Nanjing University School of Chemistry, Chinese Academy of Sciences, Nature Catalysis Journal, 2025
Geen opmerkingen:
Een reactie posten