Novel cyanate intercalated CoBi layered double hydroxide for ultimate charge separation and superior water splitting

Abstract

The discovered photocatalysts in the last decades didn't achieve the world great goal to get clean and renewable fuel by sunlight-induced water splitting, due to their low photoactivity-related wide bandgaps and working exclusively of the infrared (IR)-radiation that accounts for 53% of sunlight. In this work, we designed novel cyanate-intercalated CoBi layered double hydroxide (CICB-LDH) nanorods as highly active IR-photocatalyst by the one-pot inclusion of highly active (Bin+)-species with Co in an organic-inorganic hybrid nanocomposite. The synthesis route leads to the formation of abundant triple bonded (CN)-groups of superior trapping functions towards the photoexcited species, and in-turn elevated water splitting performance without the need for external scavengers. Based on the diffuse reflectance and X-ray photoelectron spectroscopy (XPS) analyses, CICB-LDH owns the narrower bandgap (1.32 eV) and much higher oxidation states of (Bi) compared to all the reported Co/Bi-structures, leading to superior photocatalytic activity. In the challenge oxygen evolution (OE)-reaction, CICB-LDH has achieved the maximum (OE)-rate of 5455 μmolg−1h−1 without noble co-promoters. Stacking in 1D-assembly facilitates the CICB-LDH dispersion, inter-layer water diffusion, and the (IR)-transferring during the photocatalysis. In addition, CICB-LDH shows excellent structural and photochemical stabilities as a robust layered structure for futuristic clean fuel production.