The Design,Synthesis And Hydrogen Evolution Reaction In Alkaline Solution Of Ni Assisted MoS₂/RGO Aerogels

Hydrogen has been regard as a clean energy carrier to replace fossil fuels for the mitigation of global warming.Recently,the production of hydrogen has attracted more and more interest in scientific and applied research as it is associated with renewable energy storage without the emission of carbon dioxide.The water splitting through the electrocatalysts is one of the most promising method toward highly efficient producing hydrogen.Pt metal is one of the optimal catalysts for HER as a truism.However,the scarcity of Pt has confined its application in large scale.It is very urgent to develop renewable and clean energy alternatives.Great efforts have been made to explore the highly active,low-cost,and earth-abundant non-noble metal catalysts to replace the Pt-based noble metal.More recently,molybdenum disulfide has received tremendous attention due to its promising performance as nonprecious HER catalysts.MoS₂ belongs to a large family of two-dimensional?2D?layered transition metal dichalcogenide materials,which has been widely used for energy storage and hydrogen evolution.However,inherent accumulation characteristics of MoS₂ layers seriously reduce the number of exposure active site.In addition,the conductivity which along two vertical stack S-Mo-S interlayers is extremely low.Therefore,it is critical to increase the edge of the exposed active site and prevent MoS₂ layers from stacking and reunion.Herein,we introduce an active catalyst composed of 3D Ni assisted MoS₂/RGO hybrid aerogels,exhibiting high catalytic performance and superior stability for electrocatalytic HER in alkaline solution.1.Active and durable electrocatalysts hydrogen evolution reaction?HER?in alkaline are of critical importance to the commercial viability of hydrogen fuel cell technology.Here we report a 3D MoS₂/RGO aerogel as active catalyst for HER,which has been synthesized through a facile two-step method.The 3D MoS₂/RGO birnary hybrids can provide a possible solution for the long-standing issue.MoS₂ are known to better facilitate water dissociation and the RGO can provide excellent conductivity.So,the synergy effect between MoS₂ and RGOcan promote HER performance.The optimal?₁₀in 1 M KOH is only 225 mV,the MoS₂/RGO aerogel still keep highly active with a 243 mV of?₁₀after a constant current?10mA/cm²?electrolysis for 24 h,indicating an exceptionally stable HER.Tafel slope is evaluated to be 79 mV/dec,implying that HER may carry forward along a Volmer–Heyrovsky process.2.Ni assisted MoS₂/RGO aerogel has been synthesized through another two-step facile method withsame research techniques with MoS₂/RGO aerogel except the Ni source.So,the synergy effect among Ni,MoS₂ and RGO is also shown to promote HER performance.The optimal?₁₀in 1.0 M KOH is only 170 mV.which is superior to those of recently reported non-precious electrocatalysts.Futhermore,the Ni-MoS₂/RGO aerogel still keep highly active with a 200 mV of?₁₀after a constant current?10 mA/cm²?electrolysis for 24 h,indicating an exceptionally stable HER.Tafel slope is evaluated to be 69.5 mV/dec,implying that HER may carry forward along a Volmer–Heyrovsky process.