Abstract:

The incorporation of conductive supports is crucial for achieving superior electrocatalytic performance in transition metal sulfide (TMS) systems. However, the influence of conductive supports with different dimensions remains insufficiently explored. Hereby, quasi-1D graphene nanoribbons (GNRs) and 2D Ti₃C₂T_x-MXene are for the first time simultaneously introduced to construct a novel 3D Co₉S₈/GNRs/Ti₃C₂T_x ternary composite via a simple annealing process. Systematic characterizations reveal that the GNRs/Ti₃C₂T_x composite support endows the ternary composite with superior properties, including a unique 3D architecture, improved Co₉S₈ dispersibility, increased structural defects, and higher conductivity when compared to its binary counterparts. These advantages collectively contribute to significantly enhanced oxygen evolution reaction (OER) performance. Consequently, the Co₉S₈/GNRs/Ti₃C₂T_x catalyst delivers an overpotential of 285 mV at 10 cm^-2 and a Tafel slope of 78 mV dec^-1, surpassing other comparative catalysts and approaching the performance of commercial RuO₂ catalyst. Additionally, it exhibits remarkable stability, with a negligible overpotential increase of only 2 mV during a 24 h durability test. When employed as an anode catalyst in water-splitting devices, the Co₉S₈/GNRs/Ti₃C₂T_x catalyst requires a low overpotential of 343 mV, manifesting substantial potential for water electrolysis. This work not only reports an excellent OER catalyst, but also offers a valuable strategy for designing high-performance ternary composites for energy-related reactions.

Key words: 3D Co₉S₈/GNRs/Ti₃C₂T_x composite, Conductive supports, OER performanceWater-splitting devices