Solution-Plasma-Assisted Bimetallic Oxide Alloy Nanoparticles of Pt and Pd Embedded within Two-Dimensional Ti3C2Tx Nanosheets as Highly Active Electrocatalysts for Overall Water Splitting

Exploiting high-efficiency and low-cost bifunctional electrocatalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) has been actively encouraged because of their potential applications in the field of clean energy. In this paper, we reported a novel electrocatalyst based on an exfoliated two-dimensional (2D) MXene (Ti₃C₂T _x) loaded with bimetallic oxide alloy nanoparticles (NPs) of Pt and Pd (represented by PtO _aPdO _bNPs@Ti₃C₂T _x), which was synthesized via solution plasma (SP) modification. The prepared materials were then utilized as highly efficient bifunctional electrocatalysts toward the HER and OER in alkaline solution. At a high plasma input power (200 W), bimetallic oxide alloy nanoparticles of Pt and Pd or nanoclusters with different metallic valence states were deposited onto the Ti₃C₂T _x nanosheets. Because of the synergism of the noble-metal NPs and the Ti₃C₂T _x nanosheets, the electrocatalytic results revealed that the as-prepared PtO _aPdO _bNPs@Ti₃C₂T _x nanosheets under the plasma input power of 200 W for 3 min only required a low overpotential to attain 10 mA cm^-2 for the HER (-26.5 mV) in 0.5 M H₂SO₄ solution and OER (1.54 V) in 0.1 M KOH solution. Moreover, water electrolysis using this catalyst achieved a water splitting current density of 10 mA cm^-2 at a low cell voltage of 1.53 V in 1.0 M KOH solution. These results suggested that the hybridization of the extremely low usage of PtO _a/PdO _b NPs (1.07 μg cm^-2) and Ti₃C₂T _x nanosheets by SP will expand the applications of other clean energy reactions to achieve sustainable energy.