Self-healing and high reusability of Au nanoparticles catalyst based on supramolecular hydrogel

In this work, supramolecular hydrogels were utilised as soft reactor for gold nanoparticles (Au NPs) to prepare cucurbit[8]uril (CB[8]) based supramolecular hydrogel loaded with Au NP(Au/CB[8] hydrogel) catalysts. The morphology and structure of the catalysts were characterized via UV-vis spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray powderdiffraction and thermo gravimetric analyzer analysis. The Au/CB[8] hydrogels were utilised as catalysts and reaction media for the reduction reactions of 4-nitrophenol (4-NP) with NaBH4 aqueous. The reduction rate constants at four temperatures (16 degrees C, 25 degrees C, 34 degrees C and 43 degrees C) and the activation parameters were calculated. The activation energy of 4-NP was 65.83 kJ mol(-1). These types of hydrogel-composite catalyst systems exhibit self-healing and can be used repetitively up to seven times with 100% conversion and only 20% reduction in the initial reduction rate. This process provides a novel method for the production of highe fficiency and self-healing nanomaterals with various applications.