Bioinspired Noncyclic Transfer Pathway Electron Donors for Unprecedented Hydrogen Production

Electron donors are widely exploited in visible-light photocatalytic hydrogen production. As a typical electron donor pair and often the first choice for hydrogen production, the sodium sulfide-sodium sulfite pair has been extensively used. However, the resultant thiosulfate ions consume the photogenerated electrons to form an undesirable pseudocyclic electron transfer pathway during the photocatalytic process, strongly limiting the solar energy conversion efficiency. Here, we report novel and bioinspired electron donor pairs offering a noncyclic electron transfer pathway that provides more electrons without the consumption of the photogenerated electrons. Compared to the state-of-the-art electron donor pair Na₂S-Na₂SO₃, these novel Na₂S-NaH₂PO₂ and Na₂S-NaNO₂ electron donor pairs enable an unprecedented enhancement of up to 370% and 140% for average photocatalytic H₂ production over commercial CdS nanoparticles, and they are versatile for a large series of photocatalysts for visible-light water splitting. The discovery of these novel electron donor pairs can lead to a revolution in photocatalysis and is of great significance for industrial visible-light-driven H₂ production.