Coupling PtNi Ultrathin Nanowires with MXenes for Boosting Electrocatalytic Hydrogen Evolution in Both Acidic and Alkaline Solutions

Abstract

Developing an efficient electrocatalyst for the hydrogen evolution reaction (HER) working in both acidic and alkaline solutions is highly desirable, but still remains challenging. Here, PtxNi ultrathin nanowires (NWs) with tunable compositions (x = 1.42, 3.21, 5.67) are in situ grown on MXenes (Ti3C2 nanosheets), serving as electrocatalysts toward HER. Such PtxNi@Ti3C2 electrocatalysts exhibit excellent HER performance in both acidic and alkaline solutions, with the Pt3.21Ni@Ti3C2 being the best one. Specifically, Pt3.21Ni@Ti3C2 achieves record‐breaking performance in terms of lowest overpotential (18.55 mV) and smallest Tafel slope (13.37 mV dec−1) for HER in acidic media to date. Theory calculations and X‐ray photoelectron spectroscopy analyses demonstrate that the coupling of MXenes with the NWs not only approaches the Gibbs free energy for hydrogen adsorption close to zero through the electron transfer between them in acidic media, but also provides additional active sites for water dissociation in alkaline solution, both of them being beneficial to the HER performance.

WOx‐Surface Decorated PtNi@Pt Dendritic Nanowires as Efficient pH‐Universal Hydrogen Evolution Electrocatalysts

“…Hydrogen (H 2 ), taking its high energy density and environmental friendliness into consideration, has been identified as the most promising alternative to the diminishing fossil fuel. [ 1–3 ] Hydrogen evolution reaction (HER) is of vital importance in water electrocatalysis, which produces hydrogen in a clean and sustainable way. [ 4–7 ] To minimize the overpotential and boost the kinetics of HER, an optimal electrocatalyst is highly desirable.…”

Challenges and Opportunities in Utilizing MXenes of Carbides and Nitrides as Electrocatalysts

“…[72] Additionally, the vacancies on the surface of Ti 3 C 2 T x resulting from the removal of F functional groups in the PtNi/Ti 3 C 2 catalyst can serve as active sites for water dissociation in alkaline media. [73] Using MXenes to support non-precious single metal atoms (e.g., Co/Mo 2 CT x [68] ), metal nanoparticles (e.g., Co/Ti 3 C 2 T x [74] ), or bimetallic catalysts (e.g., NiCo-Nb/Ti 3 C 2 T x [75] ) is another effective strategy for promoting HER activity. MXenes in these catalysts not only improve conductivity to increase the electron transfer rate, but also transfer electrons to the supported metals to optimize the H adsorption on the active sites.…”

Atomic Thickness Catalysts: Synthesis and Applications

“…[19,30] Graphene, an atomically thin 2D layered material, has attracted numerous attentions in diversely catalytic applications due to the ultrahigh specific surface area and high electrical conductivity. [31][32][33][34] Meanwhile, other layered ATCs have been developed as well, for example, transition metal dichalcogenides (TMDs), [20,[35][36][37][38][39] MXenes, [40,41] layered double hydroxides (LDHs), [9,27,42,43] graphdiynes (GDY), [44,45] etc. In addition, extensive researches on nonlayered nanostructured ATCs further enriched the exploration of ATCs family members.…”

“…A much lower charge transfer resistance of 1T-MoS 2 /NiS 2 NSs was observed from the Nyquist plots compared with 2H-MoS 2 / NiS 2 counterparts ( Figure 12C). Apart from the non-noble metal electrocatalysts, noble metal based ATCs have also developed via constructing alloying nanostructures (PtNi, [41,123] RuCo [23,33] ) through introducing metal-oxygen bonds as water dissociation sites [124] and incorporating H atoms. [3] Fan et al designed a metal alloy hydride of RhPd-H bimetallene NSs and it achieved highly effective performance for HER in alkaline solution.…”