Crystal Phase Control of Gold Nanomaterials by Wet-Chemical Synthesis

Abstract

Metrics & MoreArticle Recommendations CONSPECTUS: Gold (Au), a transition metal with an atomic number of 79 in the periodic table of elements, was discovered in approximately 3000 B.C. Due to the ultrahigh chemical stability and brilliant golden color, Au had long been thought to be a most inert material and was widely utilized in art, jewelry, and finance. However, it has been found that Au becomes exceptionally active as a catalyst when its size shrinks to the nanometer scale.With continuous efforts toward the exploration of catalytic applications over the past decades, Au nanomaterials show critical importance in many catalytic processes. Besides catalysis, Au nanomaterials also possess other promising applications in plasmonics, sensing, biology and medicine, due to their unique localized surface plasmon resonance, intriguing biocompatibility, and superior stability. Unfortunately, the practical applications of Au nanomaterials could be limited because of the scarce reserves and high price of Au. Therefore, it is quite essential to further explore novel physicochemical properties and functions of Au nanomaterials so as to enhance their performance in different types of applications.Recently, phase engineering of nanomaterials (PEN), which involves the rearrangement of atoms in the unit cell, has emerged as a fantastic and effective strategy to adjust the intrinsic physicochemical properties of nanomaterials. In this Account, we give an overview of the recent progress on crystal phase control of Au nanomaterials using wet-chemical synthesis. Starting from a brief introduction of the research background, we first describe the development history of wet-chemical synthesis of Au nanomaterials and especially emphasize the key research findings. Subsequently, we introduce the typical Au nanomaterials with untraditional crystal phases and heterophases that have been observed, such as 2H, 4H, body-centered phases, and crystal-phase heterostructures. Importantly, crystal phase control of Au nanomaterials by wet-chemical synthesis is systematically described. After that, we highlight the importance of crystal phase control in Au nanomaterials by demonstrating the remarkable effect of crystal phases on their physicochemical properties (e.g., electronic and optical properties) and potential applications (e.g., catalysis). Finally, after a concise summary of recent advances in this emerging research field, some personal perspectives are provided on the challenges, opportunities, and research directions in the future.

Synthesis of Pd3Sn and PdCuSn Nanorods with L12 Phase for Highly Efficient Electrocatalytic Ethanol Oxidation

“…Recently, as a representative example of phase engineering of nanomaterials (PEN), [ 23 ] noble‐metal nanostructures with unconventional crystal phases, [ 24 ] such as the 2H Au square sheets, [ 25 ] and 4H Au nanoribbons, [ 26 ] have been synthesized via wet‐chemical methods. The unique crystal phases endow them with appealing properties and promising applications in catalysis.…”

Phase engineering of metal‐organic frameworks

“…Recently, phase engineering of nanomaterials (PEN) [1] has emerged as an important strategy to modulate the atomic arrangement of nanomaterials, which can further tune their physicochemical properties and functions. [2][3][4][5][6] Via PEN, a number of polymorphic nanomaterials, including metals [7][8][9][10][11][12] and transition metal dichalcogenides [13][14][15] , and amorphous [16,17] and amorphous/crystalline heterophase nanomaterials [18][19][20] have exhibited outstanding performances in a wide range of promising applications. As a new kind of porous polymorphic materials, metal-organic frameworks (MOFs) have been extensively developed in the past decades.…”

Recent Progresses in Electrochemical Carbon Dioxide Reduction on Copper‐Based Catalysts toward Multicarbon Products

“…Recently, crystal phase control has attracted more and more attention because it can modulate the intrinsic electrical, optical, magnetic, and catalytic properties of materials. [30,[132][133][134][135][136][137][138] Importantly, crystal phase control has already been successfully applied to develop high-performance catalysts for various reactions, such as HER, oxygen reduction reaction (ORR), ethanol oxidation reaction, oxygen evolution reaction, and CO 2 RR. [139][140][141][142][143][144][145][146][147] Very recently, it was discovered that crystal phase control of Cubased catalysts can greatly affect their CO 2 RR performance for C 2+ products.…”

“…Recently, catalyst engineering has been identified as an effective strategy in modulating the CO 2 RR performance of Cu‐based catalysts. [ 20,25–27 ] So far, typical methods of catalyst engineering, such as regulating composition, [ 18,28 ] morphology, [ 29 ] crystal phase, [ 30,31 ] facet, [ 32 ] defect, [ 33 ] strain, [ 34 ] and surface and interface, [ 35 ] have been applied to promote the generation of C 2+ products on the Cu‐based catalysts. [ 36 ] In specific, catalyst engineering of Cu‐based catalysts can modulate their chemical states, atomic arrangements, surface structures, and electronic structures.…”