Engineering the Composition and Structure of Bimetallic Au–Cu Alloy Nanoparticles in Carbon Nanofibers: Self-Supported Electrode Materials for Electrocatalytic Water Splitting

Abstract

The bimetallic Au-Cu alloy nanoparticles have been constructed in electrospun carbon nanofibers (Au-Cu/CNFs), employing as high efficient hydrogen evolution reaction (HER) electrode. The morphology, structure, and composition of bimetallic Au-Cu alloy can be controlled by adjusting the precursor nanofibers through a facile approach. With the increased Cu content, the Au-Cu alloy have a transition from the homogeneous AuCu alloy phase to the AuCu phase with Cu shell. The self-supported bimetallic Au-Cu/CNFs hybrid can be directly employed as electrode materials for water splitting, and it showed excellent electrochemical activity, including long-term stability, high exchange current density, and low overpotential. The outstanding HER performance could be mainly attributed to the synergistic interactions and interfacial effects of Au-Cu alloy with high densities of uncoordinated surface atoms. In addition, the fast charge transport and the fast kinetic for the desorption of the gas were originated from the self-supported three-dimensional architectures consist of integrated Au-Cu/CNFs networks. The Au-Cu/CNFs with mass ratio of 1:2 (AuCu-Cu "core-shell" alloy) obtain the lowest overpotential of 83 mV (at j = 10 mA cm), lowest Tafel slope of 70 mV dec, and highest exchange current density of 0.790 mA cm. The present investigations offer a new strategy for the design and synthesis of unique nanocrystals in energy conversion related application.

Bifunctional Electrocatalyst with 0D/2D Heterostructure for Highly Efficient Hydrogen and Oxygen Generation

“…The catalyst represents superior stability with a slightly decreased current density after 20 h. This result is likely to be caused by the H 2 adsorption on the electrode surface and the depletion of H + in the process of OER. [34] In addition, the MoS 2 QDs/CoSe 2 electrocatalyst still has an almost constant current signal even after 1000 cycles, further verifying its excellent stability. Furthermore, the morphology of MoS 2 QDs/ CoSe 2 hybrid doesn't change significantly after OER test (Figure S8b in Supporting Information).…”

Self-assembly of Au/MoS2 quantum dots core-satellite hybrid as efficient electrocatalyst for hydrogen production

“…As shown in the inset of Fig. 8a, Au/MoS 2 QDs hybrid exhibited a slight loss of the current density after 1000 cycles, which may be ascribed to the H 2 adsorption on the catalyst surface and the depletion of H + during the test process [37]. As shown in Fig.…”

Recent Advances in 1D Electrospun Nanocatalysts for Electrochemical Water Splitting

“…The addition of Ni or Cu atom in the Pt/CNFs could enhance the HER activity due to the synergistic effect between Pt and non‐noble metal atom, the uniform distribution of the alloy NPs. [ 88–90 ] Meanwhile, Wang et al [ 90 ] proved that the morphology, structure, and composition of bimetallic Au–Cu alloy could be controlled by adjusting the Cu addition, and that the Au–Cu alloy have a transition from homogenous AuCu 3 alloy phase to Au 3 Cu phase with Cu shell with the increased Cu contents. As shown in Figure a–c, abundant uniform alloy NPs were homogeneously and densely germinated throughout the whole CNFs and no obvious agglomerated particle on the surface of CNFs.…”