119th General Meeting of the KCS

Type Poster Presentation
Area 물리화학
Room No. 포스터발표장
Time 4월 20일 (목요일) 11:00~12:30
Code PHYS.P-19
Subject Fabrication of morphology-controlled Ag/Au nanocomposites via modified galvanic replacement for enhanced catalytic performances
Authors 박태현, 이재원, 장두전*
서울대학교 화학부, Korea
Abstract Metallic nanostructures composed of noble metals have received a great deal of research effort due to their potential applicability in variety of fields such as optoelectronics, sensing, bio-labelling, and catalysis which comes from the remarkable structure-dependent properties that are considerably distinct from the bulk-sized ones. Among them, hollow architectures are a particularly interesting class of materials that have unusual chemical and physical properties compared to the respective ones of solid counterparts. Herein, morphology-controlled Ag/Au nanocomposites have been fabricated facilely via a modified galvanic replacement reaction using Ag nanocubes as sacrificial templates. The structures of the Ag/Au nanocomposites produced at galvanic reaction temperatures of 0, 25, 55, 85, and 105 oC have been found as Au-decorated Ag nanocubes, well-defined nanoboxes, truncated nanoboxes, and porous nanoboxes, and broken nanoboxes, respectively. Compared to pristine Ag nanocubes or Ag/Au nanocomposites without cavities, Ag/Au nanocatalysts with hollow interiors have been found to catalyze the reduction of rhodamine B much more rapidly in the presence of KBH4. In particular, Ag/Au nanocomposites fabricated at 85 oC show the most efficient catalytic performances as their largest nanocavities are surrounded by the most porous walls. The high enhancement of catalytic performances is attributed to the facilitation of rapid electron relays from BH4– to rhodamine B through the catalytic surface, lowering the kinetic barrier of the catalytic reaction consequently.
E-mail biglamp@snu.ac.kr