Solution-Plasma-Assisted Bimetallic Oxide Alloy Nanoparticles of Pt and Pd Embedded within Two-Dimensional Ti₃C₂T_x Nanosheets as Highly Active Electrocatalysts for Overall Water Splitting

Abstract

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 (TiCT ) loaded with bimetallic oxide alloy nanoparticles (NPs) of Pt and Pd (represented by PtOPdO NPs@TiCT ), 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 TiCT nanosheets. Because of the synergism of the noble-metal NPs and the TiCT nanosheets, the electrocatalytic results revealed that the as-prepared PtOPdO NPs@TiCT nanosheets under the plasma input power of 200 W for 3 min only required a low overpotential to attain 10 mA cm for the HER (-26.5 mV) in 0.5 M HSO 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 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 /PdO NPs (1.07 μg cm) and TiCT nanosheets by SP will expand the applications of other clean energy reactions to achieve sustainable energy.

Surface Modified MXene‐Based Nanocomposites for Electrochemical Energy Conversion and Storage

“…However, in practical HER application, the noble metal–based electrocatalysts (such as Pt) still represent the best performance. As reported by Zhang and co‐workers, the PtO a PdO b bimetallic oxide alloy nanoparticles were deposited on Ti 3 C 2 T m MXene surface, which showed enhanced HER performance comparing to pristine Ti 3 C 2 T m MXene . The PtO a PdO b nanoparticles@Ti 3 C 2 T m required η of 26.5 and 57 mV to reach a current density of 10 mA cm −2 in 0.5 m H 2 SO 4 and 1 m KOH solutions, respectively.…”

“…However, though Mahmoud and co‐workers reported a similar work in this year, the origination of the reducibility in Ti 3 C 2 T m MXene was still unclear . Zhang and co‐workers deposited bimetallic oxide alloy nanoparticles (PtO a PdO b ) on the Ti 3 C 2 T m MXene surface via a solution plasma treatment . Qiu and co‐workers tried to stabilize the Ti 3 C 2 T m MXene nanosheets via a surface carbon nanoplating method .…”

“…When turning to the OER, the most stable catalysts are the metal oxide and hydroxide species. However, as exampled by the noble metal–containing PtO a PdO b nanoparticles@Ti 3 C 2 T m composites, a η of 310 mV was required in 0.1 m KOH, which was higher than the commercial RuO 2 catalyst (η = 150 mV) . This result suggests that for the MXene‐based OER catalysts, noble metal–based modified species might not always be the best choice.…”

A Review on the Promising Plasma-Assisted Preparation of Electrocatalysts

“…It was found that the ORR activity in the electrolytes of 0.1 M KOH and 0.05 M H 2 SO 4 were three and two times higher than that in commercial Pt/C, respectively. Cui et al [40] prepared PtO a PdO b @Ti 3 C 2 T x catalysts by loading PtPd bimetallic oxide nanoparticles onto two-dimensional MXene carrier by solution plasma reduction, as shown in Figure 6. The particle size of PtPb nanoparticles increased with the extension of plasma reaction time.…”

“…TEM and HRTEM images with 200 W plasma for ( b , e ) 1 min, ( c , f ) 3 min, and ( d , g ) 5 min. ( e – g ) corresponding fast fourier transform (FFT) diffraction patterns [40]. (Reproduced with permission from [40].…”