Gold and Silver Bimetallic Core-shell Nanoparticles with a Polydopamine Interface as an Ideal Catalytic Nanosystem

Aslı Yılmaz

Abstract
Öz

Core-shell nanoparticle systems with their flexible and unique properties have been employed in various applications especially in catalytic conversion. However, the simple, low-cost, and novel strategies to prepare these nanosystems are still limited and the efficient core-shell nanostructures are highly demanded. In this study, I propose the production of the core-shell bimetallic nanosystem of gold and silver through a thin layer of polydopamine (PDOP). The PDOP layer as interphase provided efficient performance as a reducing and stabilizing agent. The fabrication of the bimetallic core-shell system was confirmed via electron microscope images and UV-vis absorption spectra. The catalytic activity tests, the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP), of the nanostructures indicated that the emergence of the core-shell system dramatically enhanced the progress of the reaction. It was also noticed that silver reduction time has a significant effect on the catalytic performances of the proposed nanosystem. Total conversion of 4-NP to 4-AP was observed within only 20 min for the case of 60 min of silver reduction time.

Çekirdek-kabuk nanopartikül sistemler esnek ve sıradışı özellikleri ile başta katalitik dönüşüm olmak üzere farklı alanlarda kullanılmaktadır. Fakat, bu nanosistemleri üretmek için basit, düşük maliyetli ve yenilikçi stratejiler sınırlı sayıda olup, etkin çekirdek-kabuk nanoyapılar yüksek oranda talep görmektedir. Bu çalışmada ince bir polidopamin (PDOP) tabakası ile oluşturulan bimetalik altın ve gümüş çekirdek-kabuk nanosistemin üretimini önermekteyim. PDOP tabakası bir ara tabaka olarak indirgeme ve stabilize ajan olarak etkin bir performans sunmuştur. Bimetalik çekirdek-kabuk sistemin üretimi elektron mikroskop görüntüleri ve UV-vis absorpsiyon spektrası ile doğrulanmıştır. Nanoyapıların katalitik aktivite testleri, 4-nitrofenolün (4-NP) 4-aminofenole (4-AP) indirgenmesi, çekirdek-kabuk sisteminin tepkimenin ilerlemesini arttırdığı gösterilmiştir. Ayrıca, gümüş indirgeme süresinin önerilen nanosistemin katalitik performansı üzerinde önemli etkiye sahip olduğu gözlenmiştir. 60 dakika gümüş indirgeme süresi için 4-NP’nin 4-AP’ye tamamen dönüşümünün sadece 20 dakikada gerçekleştiği görülmüştür.

Volume 49 - Issue 4 - 375 - 383

Gold and Silver Bimetallic Core-shell Nanoparticles with a Polydopamine Interface as an Ideal Catalytic Nanosystem

İdeal bir Katalitik Nanosistem olarak Polidopamin Arayüzlü Altın ve Gümüş Bimetalik Çekirdek-Kabuk Nanopartiküller