Hybrid Transition Metal Dichalcogenide/Graphene Microspheres for Hydrogen Evolution Reaction.

Marco Lunardon,Dario Mosconi,Hesheng Xia,JiaJia Ran,Gaetano Granozzi,Zhanhua Wang,Carla Marega,Stefano Agnoli

doi:10.3390/nano10122376

Marco Lunardon, Dario Mosconi + Show 6 more

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https://doi.org/10.3390/nano10122376

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Journal: Nanomaterials	Publication Date: Nov 28, 2020
Citations: 11	License type: CC BY 4.0

Affiliation: University of Padua, Sichuan University

Abstract

A peculiar 3D graphene-based architecture, i.e., partial reduced-Graphene Oxide Aerogel Microspheres (prGOAM), having a dandelion-like morphology with divergent microchannels to implement innovative electrocatalysts for the hydrogen evolution reaction (HER) is investigated in this paper. prGOAM was used as a scaffold to incorporate exfoliated transition metals dichalcogenide (TMDC) nanosheets, and the final hybrid materials have been tested for HER and photo-enhanced HER. The aim was to create a hybrid material where electronic contacts among the two pristine materials are established in a 3D architecture, which might increase the final HER activity while maintaining accessible the TMDC catalytic sites. The adopted bottom-up approach, based on combining electrospraying with freeze-casting techniques, successfully provides a route to prepare TMDC/prGOAM hybrid systems where the dandelion-like morphology is retained. Interestingly, the microspherical morphology is also maintained in the tested electrode and after the electrocatalytic experiments, as demonstrated by scanning electron microscopy images. Comparing the HER activity of the TMDC/prGOAM hybrid systems with that of TMDC/partially reduced-Graphene Oxide (prGO) and TMDC/Vulcan was evidenced in the role of the divergent microchannels present in the 3D architecture. HER photoelectron catalytic (PEC) tests have been carried out and demonstrated an interesting increase in HER performance.

Highlights

In the last decade, materials characterized by pores of different size and shapes have received considerable attention from both the academic and industrial world
We report on the preparation of an innovative hybrid electrocatalyst coupling transition metals dichalcogenide (TMDC) nanosheets with dandelion-like partial reduced-Graphene Oxide Aerogel Microspheres (prGOAM) (TMDC/prGOAM) by electrospray and freeze casting techniques
When the nebulized cone encounters the cold receiving solution, the spherical water microdroplets quickly freeze converting into graphene oxide (GO) ice microspheres, which were recovered through a metallic sieve and transferred into a cooled vial to avoid the thaw of the sample

Summary

Introduction

Materials characterized by pores of different size and shapes have received considerable attention from both the academic and industrial world. Among the various G based 3D architectures, G aerogels combine the exceptional intrinsic G properties with the specific properties of aerogels (lightness, low dielectric permittivity, etc.) [11,12,13,14] In recent years, they have been extensively studied, and the synthesis strategies can be divided into three categories: chemical vapor deposition (CVD) [15,16], self-assembly [17,18,19] and direct assembly via a template [20,21,22]

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