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

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 AuCu₃ alloy phase to the Au₃Cu 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 (Au₃Cu–Cu “core-shell” alloy) obtain the lowest overpotential of 83 mV (at <i>j</i> = 10 mA cm^–2), lowest Tafel slope of 70 mV dec^–1, and highest exchange current density of 0.790 mA cm^–2. The present investigations offer a new strategy for the design and synthesis of unique nanocrystals in energy conversion related application

WO_3–<i>x</i> Nanoplates Grown on Carbon Nanofibers for an Efficient Electrocatalytic Hydrogen Evolution Reaction

The search for non-noble metal catalysts with high activity for the hydrogen evolution reaction (HER) is crucial for efficient hydrogen production at low cost and on a large scale. Herein, we report a novel WO_3–<i>x</i> catalyst synthesized on carbon nanofiber mats (CFMs) by electrospinning and followed by a carbonization process in a tubal furnace. The morphology and composition of the catalysts were tailored via a simple method, and the hybrid catalyst mats were used directly as cathodes to investigate their HER performance. Notably, the as-prepared catalysts exhibit substantially enhanced activity for the HER, demonstrating a small overpotential, a high exchange current density, and a large cathodic current density. The remarkable electrocatalytic performances result from the poor crystallinity of WO_3–<i>x</i>, the high electrical conductivity of WO_3–<i>x</i>, and the use of electrospun CNFs. The present work outlines a straightforward approach for the synthesis of transition metal oxide (TMO)-based carbon nanofiber mats with promising applications for the HER