Building 3D Interconnected MoS₂ Nanosheet–Graphene Networks Decorated with Rh Nanoparticles for Boosted Methanol Oxidation Reaction

Abstract

The development of direct methanol fuel cell technology is one of the important ways to establish green energy production and conversion systems, while its large-scale commercial applications are severely hindered by the high cost and insufficient performance of current Pt-based anode catalysts. Here, we report the design and construction of a novel non-Pt electrocatalyst made from three-dimensional (3D) interconnected MoS2 nanosheet–reduced graphene oxide networks decorated with ultrafine Rh nanoparticles (Rh/MoS2-RGO) via a controllable co-assembly strategy. With unique structural features such as large specific surface areas, 3D interweaving porous frameworks, uniform Rh distribution, and excellent electron conductivity, the optimized Rh/MoS2-RGO catalyst is endowed with boosted electrocatalytic methanol oxidation properties, including a large electrochemical active surface area of 95.5 m2 g–1, a high mass (specific) activity of 1502.0 mA mg–1 (1.57 mA cm–2), and robust long-term stability, all of which significantly outperform those of reference Rh/RGO, Rh/carbon black, Rh/MoS2, as well as commercial Pt/carbon black and Pd/carbon black catalysts with the same metal content.

Stereoassembly of ultrasmall Rh-decorated zeolite imidazolate framework–MXene heterostructures for boosted methanol oxidation reaction

“…Remarkably, the largest ECSA value of up to 161.5 m 2 g −1 was achieved for the Rh/ZIF–MX (1 : 1) electrode (Table S1†), followed by Rh/ZIF–MX (3 : 1) (137.8 m 2 g −1 ), Rh/ZIF–MX (1 : 3) (130.1 m 2 g −1 ), Rh/ZIF–MX (5 : 1) (116.4 m 2 g −1 ), and Rh/ZIF–MX (1 : 5) (90.2 m 2 g −1 ). Meanwhile, the Rh/ZIF–MX (1 : 1) electrode also exhibited a remarkably large ECSA value compared with those of conventional Rh/RGO (62.1 m 2 g −1 ), Rh/CNT (41.7 m 2 g −1 ), and Rh/C (39.2 m 2 g −1 ), as well as the recent state-of-the-art Rh-based nanostructures, such as Rh nanosheets, 42,43 Rh nanotubes, 44 Rh nanodendrites, 45 Rh/carbon nanohorns, 46 Rh/CNT–RGO, 47 and Rh/MoS 2 –RGO 48 (Fig. 4b, c and Table S2†), indicating that the newly-designed ZIF/MX matrix with a rational composition was able to expose more Rh active sites than those in previously known materials.…”

Hydrothermal synthesis of polyaniline nanospheres coupled with graphene oxide for enhanced specific capacitance performances

“…The 3D structure constructed by PANI and GO can effectively avoid the re-stacking of nanosheets. 43–46…”

“…The 3D structure constructed by PANI and GO can effectively avoid the re-stacking of nanosheets. [43][44][45][46] The Raman spectra of PANI-S-a shows that the peak at 1189 cm -1 corresponds to the C-H bending vibrations of the benzenoid ring (Figure 7(a)). 47 The peaks at 1252 cm -1 and 1553 cm -1 correspond to the stretching vibration of C-N and the N-H bending vibrations of the quinoid rings, respectively.…”

Ultrafine Rh nanocrystals immobilized on 3D boron and nitrogen co-doped graphene–carbon nanotube networks: high-efficiency electrocatalysts towards the methanol oxidation reaction

“…25,26 To overcome the above barrier, Rh catalysts are usually combined with a series of carbon supporting materials with a large specific surface area and excellent electrical conductivity, such as carbon black, carbon nanotubes (CNTs), and graphene. 27,28 Among them, graphene is considered as an excellent support due to its unique 2D lamellar structure and stable chemical properties. 29,30 However, since the anchoring sites on the pristine graphene surface are randomly distributed, the direct loading of Rh nanocrystals on graphene often leads to an unsatisfying Rh dispersion.…”