Au/CdS Nanocomposite through Digestive Ripening of Au and CdS Nanoparticles and Its Photocatalytic Activity

Abstract

Co-digestive ripening is a versatile strategy for the preparation of binary metal nanoparticles such as core-shell, composites, and alloys. The mechanism of co-digestive ripening is hypothesized to involve inter-atom transfer facilitated by capping agents. In this work, co-digestive ripening of a metal (Au) and a semiconductor (CdS) system has been presented. This process involves co-refluxing of a physical mixture of Au and CdS colloids in presence of hexadecyl amine (HDA) in mesitylene solvent. Individual colloids of Au and CdS were prepared by solvated metal atom dispersion (SMAD) method. The growth control of nanoparticles using HDA resulted in the formation of monodisperse particles via a room temperature digestive ripening process. Au/CdS nanocomposite obtained via co-digestive ripening strategy was characterized by a matrix-like structure made up of CdS nanoparticles in which Au nanoparticles were embedded. CdS nanoparticles were found to establish an intimate surface contact with Au nanoparticles and the matrix of CdS surrounding Au was developed via aggregation during co-refluxing. Formation of the Au/CdS nanocomposite is proposed to involve a ligand replacement process wherein HDA molecules capping the Au surface are displaced by CdS owing to strong Au-CdS interaction. The Au/ CdS composite thus obtained showed superior photocatalytic activity compared to pure CdS nanoparticles for dye degradation reaction.[a] Dr.

Synthesis of V-doped In2O3 Nanocrystals via Digestive-Ripening Process and Their Electrocatalytic Properties in CO2 Reduction Reaction

“…Since then, digestive-ripening has become one of the most promising procedures for the preparation of monodisperse nanocrystals, particularly those of metals and semiconductors . For example, various metals (e.g., Au, In, Ag, and Pd) and semiconductors (e.g., CdS, CdSe, CsPbBr 3 , and CuSnZnS 4 ) are amenable to synthesis via the digestive-ripening process. ,− Furthermore, monodisperse metal alloy (e.g., Au–Sn, Au–Ag, and Ag–Cu), core–shell (e.g., Au@Pd and Cu@ZnO), and, more recently, composite (Au/CdS) nanocrystals have been prepared through the process. − While most of them had spherical shapes, polyhedral metal nanocrystals such as icosahedral Ag and Au and semiconducting nanocrystals such as cubic and hexagonal CdS have also been synthesized. ,, However, in contrast to the metals and semiconductors, it has been difficult to synthesize well-defined oxide nanomaterials via the digestive-ripening process . Synthesis of lanthanide oxide in the form of nanodisks was recently demonstrated, but other reports are scarce …”

Recent Developments in Detoxification of Organic Pollutants Using CdS-based Nanocomposites

“…There are numerous studies that have been carried out on different CdS based nanocomposites. In a study it was shown that Au-CdS nanocomposite prepared via facile synthesis was able to degrade 95% rhodamine b dye under UV visible light source [136]. In other researches as well, nanocomposites like CdS-Graphene and CuS-CdS have been reported to show degradation efficiency up to 90% and 99.97%, respectively [137,138].…”

“…Also, the separation of the catalysts from the solution serves as a challenge due to the nano size of the photocatalysts. Table 1 shows how various CdS based nanocomposites are being synthesised by various methods and are being employed for UV or visible light induced photocatalysis, with considerable efficiency [136][137][138][139][140][141][142][143][144][145][146].…”

Digestive-Ripening-Facilitated Nanoengineering of Diverse Bimetallic Nanostructures

“…Recently, we attempted the synthesis of nanocomposites based on a metal (Au) and a semiconductor (CdS) by the codigestive ripening strategy. 77 Au/CdS-based heterostructures are intriguing systems to explore because they demonstrate excellent photocatalytic activity. Au nanoparticles embedded in a matrix of CdS were obtained by the codigestive ripening of Au-THF and CdS-THF colloids mixed in a ratio of 1:4 in the presence of hexadecyl amine as a digestive ripening agent.…”

“…Recently, we attempted the synthesis of nanocomposites based on a metal (Au) and a semiconductor (CdS) by the codigestive ripening strategy . Au/CdS-based heterostructures are intriguing systems to explore because they demonstrate excellent photocatalytic activity.…”