In situ synthesis of AuNPs by hyperbranched polyethyleneimine-functionalized apple pomace-derived cellulose as recyclable catalysts for 4-nitrophenol reduction

Abstract

Abstract To improve the utilization rate of apple pomace and the catalytic stability and recycling performance of gold nanoparticles (AuNPs), as well as realize the high value utilization of inexpensive materials and the reuse of expensive materials, a recyclable AuNP catalyst based on hyperbranched polyethyleneimine-dialdehyde cellulose (HPEI-DAC) was developed. We used apple pomace as raw material to extract cellulose and oxidize it into easily modifiable DAC. A novel HPEI-DAC carrier with both reduction performance and easy separation performance was successfully prepared by grafting HPEI onto DAC through a Michael addition reaction. Taking advantage of the reduction properties and special topology of HPEI-DAC, AuNPs with high stability were prepared in situ. The prepared AuNPs/HPEI-DAC had high catalytic activity and reusability, which could realize the catalytic reduction of 4-nitrophenol (4-NP) and the recovery of AuNPs after catalysis. At 25 ℃, the catalytic efficiency of AuNPs/HPEI-DAC only decreased from 100% to 91% after being reused 6 times that was, its catalytic activity did not decrease significantly. These results show that the catalyst has excellent catalytic performance and reusability in reducing 4-NP organic pollutants and is expected to be used as an ideal catalyst in environmental treatment and other fields.