General Self-Assembly Route toward Sparsely Studded Noble-Metal Nanocrystals inside Graphene Hollow Sphere Network for Ultrastable Electrocatalyst Utilization

Abstract

Herein, we rationally design and construct a novel type of sparsely studded noble-metal nanocrystals inside graphene hollow sphere network (abbreviated as noble-metal@G HSN) through an electrostatic-attraction-directed self-assembly approach. The formation of Pt@G and Pd@G hollow sphere networks have been illustrated as examples using SiO2 spheres as templates. Moreover, the electrocatalytic performance of the Pt@G HSN for methanol oxidation reaction has been examined as a proof-of-concept demonstration of the compositional and structural superiorities of noble-metal@G HSN toward electrocatalyst utilization. The as-prepared Pt@G HSN manifests higher catalytic activity and markedly enhanced long-term durability in comparison with commercial Pt/C catalyst.

Nitrogen-Doped Graphene Aerogel Microspheres Used as Electrocatalyst Supports for Methanol Oxidation

“…The above results suggest that micron-sized rGNAMs-III can significantly enhance the number of reaction sites of the catalyst and improve the catalytic efficiency of Pt owing to the uniform loading of Pt NPs and the smaller particle size of Pt NPs. Importantly, in a relative comparison with Pt NPs on carbon-based 3D graphene and 3D nitrogen-doped graphene supports reported in some recent literature syudies ,,− (Figure l), Pt/rGNAMs-III reported in this study possesses a higher mass activity for the MOR. Based on the systematic studies and analysis, it can be reasonably predicted that the optimized Pt/rGNAMs are very suitable for use as methanol oxidation catalysts owing to the unique structural features.…”

Achieving Highly Electrocatalytic Performance by Constructing Holey Reduced Graphene Oxide Hollow Nanospheres Sandwiched by Interior and Exterior Platinum Nanoparticles

“…35−39 Recently, we have developed a general approach to fabricate 3D hollow GO nanospheres decorated with noble metal nanoparticles by employing SiO 2 nanospheres as templates. 24,31 Because of the minimized corrugation and excellent structural integrity, the resultant 3D hybrid hollow nanospheres exhibit greatly enhanced performances with respect to the 2D graphene sheets-based counterparts for electrocatalysis. However, in such formed architecture, the interior surface of the GO hollow nanospheres cannot be effectively utilized due to the intact wall and closed sphere.…”

“…To address these issues, rational design of three-dimensional (3D) graphene-based materials can not only inherit excellent intrinsic properties of 2D graphene but also generate some new intriguing properties, including prevented nanosheet restacking, enhanced mechanical robustness, and fast mass/electron transport kinetics, which are expected to make great contributions to the enhancement of electrocatalytic performance. − To date, various synthetic strategies, such as self-assembly approach, hard template-engaged synthesis, and chemical vapor deposition (CVD) method, have been developed for the fabrication of 3D graphene-based nanoarchitectures for diverse applications. − Recently, we have developed a general approach to fabricate 3D hollow GO nanospheres decorated with noble metal nanoparticles by employing SiO 2 nanospheres as templates. , Because of the minimized corrugation and excellent structural integrity, the resultant 3D hybrid hollow nanospheres exhibit greatly enhanced performances with respect to the 2D graphene sheets-based counterparts for electrocatalysis. However, in such formed architecture, the interior surface of the GO hollow nanospheres cannot be effectively utilized due to the intact wall and closed sphere.…”