Visible Light-Driven Conversion of Carbon-Sequestrated Seawater into Stoichiometric CO and HClO with Nitrogen-Doped BiOCl Atomic Layers.

Seawater is one of the most important CO2 sequestration media for delivering value-added chemicals/fuels and active chlorine; however, this scenario is plagued by sluggish reaction rates and poor product selectivity. Herein, we first report the synthesis of nitrogen-doped BiOCl atomic layers to directly split carbon-sequestrated natural seawater (Yellow Sea, China) into stoichiometric CO (92.8 µmol h-1) and HClO (83.2 µmol h-1) under visible light with selectivities greater than 90%. Photoelectrons enriched on the exposed BiOCl{001} facet kinetically facilitate CO2-to-CO reduction via surface-doped nitrogen bearing Lewis basicity. Photoholes, mainly located on the lateral facets of van der Waals gaps, promote the selective oxidation of Cl- into HClO. Sequestrated CO2 also maintains the pH of seawater at around 4.2 to prevent the alkaline earth cations from precipitating. The produced HClO can effectively kill typical bacteria in the ballast water of ocean-going cargo ships, offering a green and safe way for onsite sterilization.