Fabrication of graphene nanoplatelets/MgAl-layered double hydroxide nanocomposites as efficient support for gold nanoparticles and their catalytic performance in 4-nitrophenol reduction

The catalytic reduction of 4-nitrophenol is of considerable importance to a multitude of applications and in-dustries. The present work introduces a new catalyst (AuNP/GNP/MgAl-LDH) containing gold nanoparticles (AuNP) supported on graphene nanoplatelets (GNP) intercalated in Mg Al layered double hydroxides (MgAl-LDH) for the reduction of 4-nitrophenol to 4-aminophenol using NaBH4 as a reducing agent. The catalyst was characterised by FTIR, XRD, STEM, TEM, and BET specific surface area. The XRD analysis showed the presence of crystalline phases of gold on the supports, while TEM demonstrated that MgAl-LDH provided uniform binding sites for AuNPs and prevented agglomeration. Similar reaction rate constant was determined for the disap-pearance of 4-nitrophenol and for the appearance of 4-aminophenol. The reaction rate constant was the highest for AuNP/GNP/MgAl-LDH, followed by AuNP/MgAl-LDH and AuNP/GNP. AuNP/GNP/MgAl-LDH was found stable after five repeated cycles.

Automated summary

The study presents a new catalyst (AuNP/GNP/MgAl-LDH) consisting of gold nanoparticles (AuNP) supported on graphene nanoplatelets (GNP) intercalated in MgAl layered double hydroxides (MgAl-LDH). The catalyst was used for the reduction of 4-nitrophenol to 4-aminophenol using NaBH4 as a reducing agent. Characterization techniques such as FTIR, XRD, STEM, TEM, and BET specific surface area were employed. The results showed that AuNP/GNP/MgAl-LDH exhibited the highest reaction rate constant and stability after five repeated cycles.