Continuous Flow Vortex Fluidic Fabrication of Crumpled rGO/MoS2 Composites for Hydrogen Evolution Catalysis
Thaar M. D. Alharbi, Amjad E. H. Alotaibi, Mohammed Alahmadi, Renad Almuqhathawi, Mahmoud Moussa, Shan He, Mazen R. Alrahili, Nessrin A. Kattan, Colin L. RastonAbstract
High-yield crumpled reduced graphene oxide (rGO)/MoS2 composites were produced using continuous-flow processing in a vortex fluidic device (VFD) without surfactants or additional reagents. Intense shear within the dynamic thin film enabled rapid composite formation, generating uniform crumpled structures (0.7−3 μm) by simultaneously jet feeding DMF solutions of MoS2 and rGO into a 45° tilted rotating tube. The formation of the composite material aligns with established VFD topological flow models, where shear-induced desolvation and interfacial interactions along with high local pressures and temperatures drive sheet crumpling and assembly. This method is scalable, achieving conversion efficiencies of up to ∼95%. The resulting crumpled rGO/MoS2 structures show promising electrocatalytic activity for the hydrogen evolution reaction, achieving low overpotentials and a Tafel slope of 119 mV dec−1, highlighting their potential as cost-effective water-splitting catalysts.