Tapping hydrogen fuel from the ocean: A review on photocatalytic, photoelectrochemical and electrolytic splitting of seawater

Direct splitting of earth-abundant seawater provides an eco-friendly route for the production clean H 2 , but is hampered by selectivity and stability issues. electrolysis most established technology, attaining high current densities in order 1–2 A cm ?2 . Alternatively, light-driven processes such as photocatalytic photoelectrochemical are particularly promising well, they rely on renewable solar power. Solar-to-Hydrogen efficiencies have increased over past decade from negligible values to about 2%. Especially absence large local pH changes (in several tenths a unit compared up 9 units electrolysis) strong asset pure photocatalysis. This may lead less adverse side-reactions Cl ClO ? formation, (acid or base induced) corrosion scaling. Besides, additional requirements electrolytic cells, e.g. membranes electricity input, not needed photocatalysis systems. In this review, state-of-the-art technologies electrochemical approaches with focus sustainability stability. Promising advances identified at level catalyst well process, insight provided solutions crossing different fields. The pros cons electrolytic, compared, highlighting technological aspects. • Review splitting. Activity, selectivity, all compared. Electrolysis more mature, while experience side effects. across fields identified.