Heterophase fcc-2H-fcc gold nanorods

Abstract

The crystal phase-based heterostructures of noble metal nanomaterials are of great research interest for various applications, such as plasmonics and catalysis. However, the synthesis of unusual crystal phases of noble metals still remains a great challenge, making the construction of heterophase noble metal nanostructures difficult. Here, we report a one-pot wetchemical synthesis of well-defined heterophase fcc-2H-fcc gold nanorods (fcc: face-centred cubic; 2H: hexagonal close-packed with stacking sequence of "AB") at mild conditions. Single particle-level experiments and theoretical investigations reveal that the heterophase gold nanorods demonstrate a distinct optical property compared to that of the conventional fcc gold nanorods. Moreover, the heterophase gold nanorods possess superior electrocatalytic activity for the carbon dioxide reduction reaction over their fcc counterparts under ambient conditions. First-principles calculations suggest that the boosted catalytic performance stems from the energetically favourable adsorption of reaction intermediates, endowed by the unique heterophase characteristic of gold nanorods.

Phase Engineering of Nanomaterials for Clean Energy and Catalytic Applications

“…Therefore, the unconventional 2H phase and the 2H/fcc interface in fcc-2H-fcc Au NRs are essential to their superior catalytic performance in CO 2 RR. [90] In a recent work, we have demonstrated the crystal phasedependent C 2 H 4 selectivity of Cu nanomaterials in the CO 2 RR (Figure 3g-l). [91] Specifically, by using 4H and 4H/fcc Au nanostructures as templates, the 4H and 4H/fcc Au@Cu core-shell nanomaterials were successfully synthesized (Figure 3g).…”

“…Photocatalytic reaction provides a sustainable way for many applications, such as energy conversion and pollutant Reproduced with permission, [90] Copyright 2020, Springer Nature. g) Schematic illustration of the 4H and 4H/fcc Au@Cu core-shell nanostructures.…”

“…Recently, our group found that Au nanorods (NRs) with heterophase possess enhanced catalytic selectivity and activity in CO 2 RR ( Figure 3 a–f). [ 90 ] As shown in Figure 3a, the as‐prepared Au NR shows a well‐defined fcc‐2H‐fcc heterophase structure. When used as a catalyst for CO 2 RR, it demonstrated outstanding catalytic performance toward the CO production.…”

“…Therefore, the unconventional 2H phase and the 2H/fcc interface in fcc‐2H‐fcc Au NRs are essential to their superior catalytic performance in CO 2 RR. [ 90 ]…”

“…f) Calculated free energy diagrams for CO 2 RR on different Au surfaces. Reproduced with permission, [ 90 ] Copyright 2020, Springer Nature. g) Schematic illustration of the 4H and 4H/fcc Au@Cu core–shell nanostructures.…”