From Galvanic to Anti‐Galvanic Synthesis of Bimetallic Nanoparticles and Applications in Catalysis, Sensing, and Materials Science

Abstract

The properties of two alloyed metals have been known since the Bronze Age to outperform those of a single metal. How alloying and mixing metals applies to the nanoworld is now attracting considerable attention. The galvanic process, which is more than two centuries old and involves the reduction of a noble-metal cation by a less noble metal, has not only been used in technological processes, but also in the design of nanomaterials for the synthesis of bimetallic transition-metal nanoparticles. The background and nanoscience applications of the galvanic reactions (GRs) are reviewed here, in particular with emphasis on recent progress in bimetallic catalysis. Very recently, new reactions have been discovered with nanomaterials that contradict the galvanic principle, and these reactions, called anti-galvanic reactions (AGRs), are now attracting much interest for their mechanistic, synthetic, catalytic, and sensor aspects. The second part of the review deals with these AGRs and compares GRs and AGRs, including the intriguing AGRs mechanism and the first applications.

Liquid‐Phase Transmission Electron Microscopy for Studying Colloidal Inorganic Nanoparticles

“…Galvanic replacement is a chemical reaction in which a metal with a low reduction potential is oxidized and dissolved, while other metal ions with high reduction potentials are reduced and deposited, in the presence of an electrolyte . In 2002, Sun and Xia first reported a nanoscale galvanic replacement reaction between Ag nanocubes and Au ions .…”

Modern Chemical Routes for the Controlled Synthesis of Anisotropic Bimetallic Nanostructures and Their Application in Catalysis

“…The term galvanic was derived from an Italian physician, Luigi Galvani, a biologist, philosopher, and pioneer of bioelectricity who established the first galvanic cell in the year 1780 (Focaccia and Simili, 2007). The GRR consists of a redox process between two metals where the lesser noble metal has the tendency to reduce the more noble metal cation having a higher redox potential with a suitable driving force (Liu and Astruc, 2017). The driving force here developed from the reduction potential difference between the two different metals where one acts as a sacrificial template and the other is metal cation (Da Silva et al, 2017).…”

“…Moreover, the formation of self-accumulation structures has been gaining significant interest and suggests attractive options for the synthesis of bimetallic nanomaterials with unique functions (Rechberger and Niederberger, 2017). Unique properties developed in a single material from the manifestation of multiple metals can be used in different applications such as catalysis, sensing, thermoelectric, and electronic devices (Barakat et al, 2010;Alonso et al, 2012;Piccolo, 2012;Tao, 2012;Liu and Astruc, 2017). Diverse routes have been adapted for the synthesis of bimetallic nanoparticles, regardless of the engineering of these bimetallic structures with monodispersity.…”

Graphene nanocrystals in CO2photoreduction with H2O for fuel production

“…16 AgRh BNPs exhibited exceptional catalytic functions due to the positive synergistic effect between the Ag and Rh atoms on GQDs, 21,22 and their catalytic activity was better than those of both monometallic counterparts. This graphene exhibited outstanding generation of hydroxyl radicals [17][18][19][20] and further oxidized MB to MB-OH via some positive synergistic effects between the Ag and Rh atoms on GQDs than those of other BNPs and pure Ag or Rh NPs (Fig. 3).…”