Precisely Controlled Synthesis of Hybrid Intermetallic–Metal Nanoparticles for Nitrate Electroreduction

Abstract

Precisely controlled synthesis strategies to prepare anisotropic nanomaterials with high yield and easy operation are exceedingly in demand because hybrid structures often introduce novel properties that cannot be achieved by isotropic nanomaterials. Here, a one-pot, two-step hot injection method was developed to prepare Cu 6 Sn 5 −Sn hybrid intermetallic−metal nanoparticles with an anisotropic structure. Hybrid nanoparticles with distinguishable Sn and Cu 6 Sn 5 domains were formed under mild temperature. Different compositions of Sn and Cu 6 Sn 5 , ranging from pure Sn to various ratios of the Sn part and Cu 6 Sn 5 part to pure Cu 6 Sn 5 , were achieved by modulating the reaction conditions, the ratio of the two metals. The as-synthesized asymmetric Cu 6 Sn 5 −Sn nanoparticles show small onset potentials (0.2 V vs reversible hydrogen electrode, RHE) and high activities (1125 mA mg −1 metal at −0.2 V vs RHE) in electrocatalytic nitrate reduction reaction. Unlike reported Cu-or Sn-based catalysts in nitrate reduction, the hybrid Cu 6 Sn 5 −Sn nanoparticles selectively produce the unstable intermediate, nitrite, within a wide reduction potential window.

Synthesis of PtSn4 Intermetallic Nanodisks through a Galvanic Replacement Mechanism

“…Due to the sluggish kinetics at low temperature, part of Pt ions involved in the formation of PtSn 4 intermetallic and hybrid PtSn 4 –Sn intermetallic-metal NPs are prepared. Hybrid nanomaterials with an anisotropic structure are attractive materials in many applications such as catalysis, , self-assembly, and cancer therapy …”

“…In the developed galvanic replacement synthetic system, the PtSn 4 intermetallic phase was formed under mild temperatures, from 60 to 120 °C. As shown in Figure 4c nanomaterials with an anisotropic structure are attractive materials in many applications such as catalysis, 30,31 selfassembly, 32 and cancer therapy. 33 To explore the possibilities of synthesizing Pt−Sn nanomaterials with different shapes or intermetallic phases, various Pt to Sn ratios, including 1/10, 1/5, and 1/2, were attempted.…”

Facile and Scalable Synthesis of Self-Supported Zn-Doped CuO Nanosheet Arrays for Efficient Nitrate Reduction to Ammonium

“…5,6 Since NO 3 − RR is a multi-electron transfer process involving the generation of diverse byproducts, electrocatalysts with high activity and selectivity are necessary. 7,8 Besides, superior NO 3 − RR kinetics are also required so that to suppress the competing hydrogen evolution reaction (HER). 9 Noble metal-based catalysts, for example, Pt, Ru, and Rh, are demonstrated to show good catalytic activity toward NO 3 − RR, but their widespread applications are hindered by the high cost and competitive HER process.…”

Opportunities for Electrocatalytic CO2 Reduction Enabled by Surface Ligands

“…The past several decades have witnessed the application of nanomaterials to many fields of chemistry, especially catalysis. , Nanocatalysts have been reported to exhibit excellent catalytic reactivity and selectivity due to their high surface-to-volume ratio, tunable structure, and high surface reactivity. , The colloidal synthesis of nanoparticles usually requires a capping agent to maintain the nanostructure by binding to metal atoms and minimizing surface energies. Often this capping agent consists of small molecule surface ligands, but polymers such as PVP and PVA can also serve as capping agents. , Dendrimers are a special class of branched polymers that can stabilize nanoparticles and control the precise size control of ultrasmall nanoparticles below 1 nm in size. , In recent years many types of ligands have also been explored, , which help to maintain the nanostructure by binding to metal atoms and minimizing surface energies. ,, Significant effort has been directed toward understanding how these surface ligands influence catalytic performance. − It has been shown that ligands can influence catalytic performance through both steric and electronic effects. , Specifically, ligands can sterically constrain a particular conformation for an adsorbed intermediate or block certain reactants from reaching the catalyst surface, thus affecting the activity and selectivity. As an example, it has been shown that chiral ligands can induce enantioselectivity for hydrogenation reactions on metal surfaces by constraining the adsorption geometry of bound intermediates .…”

“…5,6 Dendrimers are a special class of branched polymers that can stabilize nanoparticles and control the precise size control of ultrasmall nanoparticles below 1 nm in size. 7,8 In recent years many types of ligands have also been explored, 9,10 which help to maintain the nanostructure by binding to metal atoms and minimizing surface energies. 4,11,12 Significant effort has been directed toward understanding how these surface ligands influence catalytic performance.…”