Morphology Control and Electro catalytic Activity towards Oxygen Reduction of Peptide‐Templated Metal Nanomaterials: A Comparison between Au and Pt

Abstract

Peptide templated noble metal nanomaterials have been considered as an emerging type of nanomaterials, which can find widespread catalytic applications in a variety of organic reactions. However, their electrocatalytic properties remained largely unexplored. Herein, peptide R5 templated Au and Pt nanomaterials were fabricated and employed as catalysts for oxygen reduction reaction (ORR). By tuning the metal-topeptide ratio, different shaped Au and Pt nanomaterials were obtained and observed by TEM measurements. With lower metal-to-peptide ratios, spherical nanoparticles were obtained for both Au and Pt, while higher metal-to-peptide ratios led to the formation of nanoribbons and/or networked nanochains. All the Au and Pt nanomaterials demonstrated good ORR activity, while R5-Au-90 and R5-Pt-90 exhibited the best performance in their own series. Morphological effects of Au and Pt nanomaterials upon ORR were established. R5-Pt-90 exhibited comparable activity with Pt/C, as manifested by the onset potential, specific activity as well as the long-term durability. The findings can shed light on rational design of peptide templated noble metal nanomaterials with desired morphology and optimized electrochemical properties as catalyst for electrochemical reactions.

Sequence-specific control of inorganic nanomaterials morphologies by biomolecules

“…In comparison to DNA molecules, peptides contain more diverse functional groups and therefore have also been employed for various inorganic nanomaterial synthesis. For example, Tang and coworkers [34] used peptide R5 (SSKKSGSYSGSKGSKRRIL) for the synthesis of Au and Pt nanoparticles. As a result, when the synthesis was performed under lower metal-to-peptide ratios, both Au and Pt nanoparticles grew into spherical shapes, whereas higher metal-to-peptide ratios yielded nanoribbons or networked nanochains.…”

Peptide‐FlgA3‐Based Gold Palladium Bimetallic Nanoparticles That Catalyze the Oxygen Reduction Reaction in Alkaline Solution

“…The synthesis of Au x Pd y (in which x/y is the Au/Pd molar ratio: 0:100, 20:80, 33:67, 50:50, 67:33, 80:20, and 100:0) alloyed NPs was conducted by following am odification of ap rocedure reported previously. [21,41] For the synthesis of Au 33 Pd 67 ,H AuCl 4 (33 mL, 0.02 m), K 2 PdCl 4 (67 mL, 0.02 m), FlgA3 solution (77 mL, 1mgmL À1 ), and H 2 O( 1723 mL) were first mixed and stirred for 15 min, then freshly prepared NaBH 4 (100 mL, 0.1 m)a queous solution was added dropwise under shaking. The solution turned from pale yellow into ac harcoal color immediately and it was left undisturbed for 1h.T he peptide-based AuPd alloyed NPs were obtained.…”

“…Besides the above examples, to date, few examples can be found. Recently, we reported the fabrication of peptide‐R5‐templated Au and Pt nanomaterials with different morphologies as highly efficient catalysts for the oxygen reduction reaction (ORR) . In addition, a series of peptide‐capped Pd NPs was fabricated to examine their ORR activity, and strong surface effects were established between the peptide sequence and the electrocatalytic activity .…”

“…peptide-R5-templated Au and Pt nanomaterials with different morphologies as highly efficient catalysts for the oxygen reductionr eaction( ORR). [21] In addition, as eries of peptidecapped Pd NPs was fabricated to examine their ORRa ctivity, and strongs urface effects were established between the peptide sequence and the electrocatalytic activity. [22] Notably,t he ORR is the pivotal step that determines the efficiency of af uel cell, [23][24][25][26][27] which is considered widely as ap romisingg reen energy device thanks to its high energy conversion efficiency, ultrahighp owerd ensity,e asy operation at low temperature, and almost no detrimental environmental impacts.…”

Facile Synthesis of Polyhedral Pd Nanocrystals as a Highly Active and Methanol-Tolerant Electrocatalyst for Oxygen Reduction

“…Therefore, it is urgent to develop an alternative catalyst replacing expensive Pt for ORR with much cheaper price, higher ORR activities, and better methanol‐tolerance ability ,. To overcome the limitations of expensive Pt‐based electrocatalysts, Pd‐based catalysts have recently attracted much more attention due to its lower cost combined with closing to the state‐of‐art Pt for ORR in alkaline solution …”