Silver nanoparticle array on weakly interacting epitaxial graphene substrate as catalyst for hydrogen evolution reaction under neutral conditions

I Shtepliuk,Jianwu Sun,N Ben Sedrine,R Yakimova,J Jian,K Sarakinos,N Pliatsikas,I G Ivanov,T Iakimov

doi:10.1063/5.0064697

Abstract

The paucity of research on hydrogen evolution reaction (HER) under neutral conditions, which is a more sustainable way to produce H2 compared to acidic and alkaline HER, encourages the development of efficient catalytic materials and devices and deeper investigation of the mechanisms behind neutral HER. We present an electrode concept for facilitating HER under neutral conditions. The concept entails the use of annealing-reshaped silver (Ag) nanoparticle array on monolayer epitaxial graphene (MEG) on 4H-SiC. Measurements of HER performance show more positive onset potential of the cathodic HER for Ag-decorated MEG compared to that for pristine MEG, indicating improved water dissociation at Ag/MEG electrodes. Complementary morphological characterization, absorption measurements, and Raman mapping analysis enable us to ascribe the enhanced catalytic performance of electrodes decorated with 2 nm thick annealed Ag on the synergetic effect originating from simultaneous water reduction on circular Ag nanoparticles of 31 nm in diameter and on compressively strained Ag-free graphene regions. The overall results pave the way toward development of stable van der Waals heterostructure electrodes with a tunable metal–carbon interaction for fast HER under neutral conditions.

Highlights

During the last decade, graphene-supported metal carbides,[9] disulfides,[10] phosphides,[11] selenides,[12] oxides,[13] and nitrides[14] have gained significant attention as appealing materials beyond Pt group metals (PGMs) electrocatalysts
Complementary morphological characterization, absorption measurements, and Raman mapping analysis enable us to ascribe the enhanced catalytic performance of electrodes decorated with 2 nm thick annealed annealing-reshaped silver (Ag) on the synergetic effect originating from simultaneous water reduction on circular Ag nanoparticles of 31 nm in diameter and on compressively strained Ag-free graphene regions
A major advantage of such systems lies in the fact that each metal nanoparticle on graphene may serve as a separate nanoelectrode, providing abundant catalytic active sites

Summary

Introduction

Graphene-supported metal carbides,[9] disulfides,[10] phosphides,[11] selenides,[12] oxides,[13] and nitrides[14] have gained significant attention as appealing materials beyond PGM electrocatalysts.

Results

Conclusion