Artificial photosynthesis mimics what leaves do — capturing sunlight and turning it into stored chemical energy — but replaces chlorophyll with engineered catalysts. A photoelectrode absorbs photons and uses that energy to split water molecules at the anode, releasing oxygen gas and electrons. Those electrons travel through an external circuit to a cathode, where a catalyst uses them to reduce captured CO₂ molecules into fuels such as carbon monoxide, methanol or light hydrocarbons.
Even the best artificial-photosynthesis devices today convert only a few percent of sunlight into fuel — still short of natural leaves in some respects, but already far more energy-dense per unit area than growing biomass, which is why it remains an active pilot-scale research field for carbon-neutral fuels.
A 3D catalytic cell where sunlight drives water oxidation at a photoanode while captured CO₂ is reduced into fuel molecules at a catalyst-coated cathode — the core mechanism behind real artificial-photosynthesis devices.
Photons absorbed at the anode free electrons that split water into oxygen, protons and electrons; those electrons travel through an external wire to the cathode, where a catalyst combines them with CO₂ and protons to build fuel molecules.
Adjust sunlight intensity, CO₂ concentration and applied bias voltage, and swap between copper, silver and copper–zinc-oxide catalysts to see how each favours a different fuel product and Faradaic efficiency.
Catalyst chemistry, not just light intensity, largely decides what comes out of the cell — copper is famous for producing a messy mix of multi-carbon products, while silver and gold are prized for near-perfect selectivity toward carbon monoxide.