Aboundent oxygen defects in CoFe-LDH derivatives for enhanced photo-thermal synergistic catalytic hydrogen production from NaBH4

Two-dimensional catalysts, which are sensitive to visible light and have a photothermal effect, can be used to catalyse the release of H2 from sodium borohydride (NaBH4) are being actively explored in energy saving systems. In this work, oxygen vacancy enriched two-dimensional CoFe-layered double hydroxide (CoFe-LDH) derivatives (named as CoFe-x degrees C, x = 200-500) have been explored for NaBH4 hydrolysis catalyzed by photo-thermal synergy without external heat source. The CoFe-300 degrees C presents its initial hexagonal lamellar structure and has the highest concentration of oxygen vacancy. These unique properties guarantee its excellent photo-thermal synergistic catalytic performance, achieving hydrogen production rate of 1877.5 mmol g-1 h-1, and maintains high effi-ciency after 5 cycles. This enhanced photo-thermal synergistic catalytic mechanism is the .OH (generated from h+ and H2O) attacks BH4- (absorbed on Ov sites) to produce H2, the heat from photothermal conversion accelerates the adsorption ability and attacking rate. This study opens a new strategy for the synergistic photo-thermal catalytic hy-drolysis of NaBH4.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

Two-dimensional catalysts with photothermal effect are being researched to catalyze the release of H2 from NaBH4 in energy saving systems. This study explores oxygen vacancy enriched CoFe-LDH derivatives for NaBH4 hydrolysis catalyzed by photo-thermal synergy. The CoFe-300 degrees C with the highest concentration of oxygen vacancy shows the best photo-thermal synergistic catalytic performance, achieving a hydrogen production rate of 1877.5 mmol g-1 h-1 and maintaining high efficiency after 5 cycles. This study reveals an enhanced photo-thermal synergistic catalytic mechanism for the hydrolysis of NaBH4.