Enhancement of the properties of ZnAl-LDHs for photocatalytic nitrogen reduction reaction by controlling anion intercalation

Layered double hydroxides (LDHs) have been shown to be efficient photocatalysts for the nitrogen fixation reaction. However, the effect of interlayer anions on the catalytic performance has not yet been reported. Herein, the anion regulated channel of LDHs blocked by carbonate (Car) was opened by controlling the suberate (Sub) intercalation, thus obtaining a series of ZnAl-LDHs with different anions (carbonate, suberate, PMo12-XVX, X = 0, 1, 2, 3, 8). The photocatalytic performance test in pure water showed that Sub@ZnAl-LDH and PMo9V3@ZnAl-LDH improved the NH3 yield from 11.37 mu mol h-1 g-1cat for Car@ZnAl-LDH to 48.91 mu mol h-1 g-1cat and 89.16 mu mol h-1 g-1cat, respectively. The improvement of the performance was attributed to the following: (1) nitrogen was allowed to enter between LDH layers due to the expansion of the interlayer spacing; (2) the hydrophobic suberic acid intercalation suppressed the hydrogen evolution reaction; (3) the POM intercalation broadened the light absorption range of LDH. In this paper, the photocatalytic properties of ZnAl-LDHs intercalated with different anions are explored and investigated for the first time, which provides a versatile strategy for enhancing the catalytic activity of LDHs in the photocatalytic nitrogen fixation reaction.

Automated summary

This study reveals the influence of different interlayer anions on the photocatalytic performance of ZnAl-LDHs, providing a new approach to enhance the catalytic activity of LDHs in the photocatalytic nitrogen fixation reaction.