In situ synthesis of AuNPs by hyperbranched polyethyleneimine-functionalized apple pomace-derived cellulose as...

4-Nitrophenol (4-NP) is recognized as a toxic and non-biodegradable organic substance. Currently, an effective approach for treating 4-NP involves reducing it to the more environmentally benign 4-aminopyridine (4-AP), utilizing the catalytic capabilities of gold nanoparticles (AuNPs). However, the treatment process faces several challenges, including the poor stability of AuNPs, the inability to recycle expensive AuNPs, and the high cost of carrier materials carrying AuNPs. To enhance the stability and recycling performance of AuNPs, as well as to identify cost-effective carrier materials, we used apple pomace as the raw material to extract cellulose and oxidize it into easily modifiable DAC. By grafting HPEI onto DAC through a Michael addition reaction, we successfully prepared a novel HPEI-DAC carrier with both reduction performance and easy separation properties. This approach not only maximized the utilization of inexpensive materials but also facilitated the reuse of expensive ones. Taking advantage of the reduction properties and special topology of HPEI-DAC, AuNPs with high stability were prepared in situ. The resulting AuNPs/HPEI-DAC exhibited remarkable catalytic activity and reusability. Impressively, even after 6 rounds of reuse, the catalytic efficiency of AuNPs/HPEI-DAC only decreased from 100 % to 91 %, demonstrating its great potential for the efficient reduction of 4-NP.