Metallic glasses (MGs), with high density of low coordination sites and high Gibbs free energy state, are novel promising and competitive candidates in the family of electrochemical catalysts. However, it remains a grand challenge to modify the properties of MGs by control of the disordered atomic structure. Recently, nanostructured metallic glasses (NGs), consisting of amorphous nanometer‐sized grains connected by amorphous interfaces, have been reported to exhibit tunable properties compared to the MGs with identical chemical composition. Here, it is demonstrated that electrodeposited Ni–P NG is characterized by an extremely high energy state due to its heterogeneous structure, which significantly promotes the catalytic performance. Moreover, the Ni–P NG with a heterogeneous structure is a perfect precursor for the fabrication of unique honey‐like nanoporous structure, which displays superior catalytic performance in the urea oxidation reaction (UOR). Specifically, modified Ni–P NG requires a potential of mere 1.36 V at 10 mA cm–2, with a Tafel slope of 13 mV dec–1, which is the best UOR performance in Ni‐based alloys. The present work demonstrates that the nanostructurization of MGs provides a universal and effective pathway to upgrade the energy state of MGs for the design of high‐performance catalysts in energy conversion.

Like crystalline materials, the properties of amorphous materials can be tailored by tuning the local atomic-to-nanoscale structural configurations. Polyamorphism is evident by the coexistence of kinetically stabilized amorphous structures with tailorable short-to-medium-range orders, providing a viable means to engineer the degree of local order and heterogeneity. Here, we report experimental evidence of the coexistence of liquid-like and solid-like amorphous phases in a Ni 82 P 18 amorphous alloy with enhanced thermal stability and plasticity prepared by pulsed electrodeposition. The two amorphous phases, of comparable volume fraction of~50% each, have similar short-range order but are distinguished by packing at the medium-range length scale (>6 Å). Upon heating, a structure crossover at 450 K was observed, where the liquid-like structure transforms to the solid-like structure, as evidenced by the enthalpy release and an anomalous contraction of atomic structure over the medium-range length scale, due to the metastable nature of the liquid-like structure.

The secondary (β) relaxation is an intrinsic feature of glassy systems and is crucial for the mechanical properties of metallic glasses. However, it remains puzzling what structural features control the β-relaxation fundamentally. Here, we use the recently developed nanoglasses exhibiting well-defined structural features at the nanometer scale to interrogate such structure−dynamics relations. We show that an electrodeposited Ni 77.5 P 22.5 nanoglass exhibits promoted β-relaxation and enhanced microscale tensile plasticity over the most rapidly meltquenched metallic glass with the same composition. Structurally, the βrelaxation is sensitive to the interfacial regions among grains in the nanoglasses. Our results reveal a clear correlation between the amorphous nanostructures and the β-relaxation. It seems that the nanostructuring represents a novel route to obtain high-energy glassy states, that is, the inverse problem of the ultrastable glass.

Direct urea/H 2 O 2 fuel cells (DUFCs) constitute a sustainable bifunctional energy conversion technique devoted to simultaneously eliminating environmental wastewater with urea and generating clean energy. However, exploring an efficient anode material for DUFCs still remains a huge challenge. In this work, a Ni−P hierarchical porous nanoglass (HPNG) catalytic electrode was developed via a low-cost, industrially available electrodeposition technique, which exhibits one of the best performances reported so far in the urea oxidation reaction (UOR), with a potential of 1.330 V at a current density of 10 mA cm −2 and a Tafel slope of 9.77 mV dec −1 . The superior UOR performance of the HPNG electrode is attributed to the excellent intrinsic catalytic activity of NG with a high-energy state and an extremely enlarged surface area from the unique 3D hierarchical porous structure. Furthermore, a DUFC system with the HPNG anode shows a performance breakthrough as indicated by the maximum power density of 38.15 mW cm −2 for 0.5 M urea, representing one of the best yet reported DUFCs. Our work demonstrates the feasibility of the scalable production of HPNG electrodes and is expected to be a great contribution to the development of the practical use of DUFCs in the near future for bifunctional energy conversion.