In situ laser-assisted synthesis of MoS2 anchored on 3D porous graphene foam for enhanced alkaline hydrogen generation

Abstract

MoS₂ is acknowledged as a promising alternative for Pt-based hydrogen evolution reaction (HER) catalysts, while its essential semiconductor nature and insufficient active edge sites weaken its intrinsic HER performance. Distributing MoS₂ on conductive graphene is expected to enhance its conductivity and enrich its active edge sites, thus endowing it with satisfactory HER performance. Carbon-based MoS₂ materials are usually fabricated via solution-based methods and thermal annealing approaches. Herein, we demonstrate in situ laser-assisted fabrication of MoS₂ on laser-induced graphene (LIG) to form LIG/MoS₂ electrocatalyst for HER promotion. After laser engraving on LIG with precursor solution, MoS₂ is easily anchored on highly porous LIG within a few minutes in the form of nanoparticles. To afford a current density of 10 mA cm⁻², LIG/MoS₂ merely requires an acceptable overpotential of 130 mV in 1.0 M KOH electrolyte, which outperforms most reported carbon-related MoS₂-based electrocatalysts. The impressive HER behavior is mainly ascribed to the porous structure and electrical conductivity of LIG, which respectively enriches active sites and facilitates charge transfer. This work not only offers us an attractive noble-metal-free HER promoter but opens a new route toward the facile synthesis of on-chip micro-fuel cells or catalytic microreactors.