Rapid Synthesis of Nickel Boride/Graphene by Microwave Thermal Shock and its Application in Hydrogen Evolution Reaction

The urgent demand for sustainable and clean energy has promoted the development of water splitting. Herein, metal borides assisted synthesis of graphene-based material (Ni-B/G) has been carried out by facile and fast microwave heating method and applied to hydrogen evolution reaction (HER) in alkaline solution. The Ni-B combining with 2D graphene give rise to highly efficient HER performance with low overpotential of 187 mV at current density of 10 mA cm−2. In addition, it exhibits good stability and retains 76% of current density after continuous oxygen release. The excellent performance is ascribed to the synergetic effect of Ni-B and graphene. The Ni-B not only acts as initiator to adsorb microwave energy but also works as active centre of catalyst. The high conductivity and large specific area of graphene offer accessible contact between electrolyte and intermediates. Therefore, Ni-B/G indicates a promising candidate for HER in alkaline media.

Elucidating the Reaction Pathway of Crystalline Multi-metal Borides for Highly Efficient Oxygen-Evolving Electrocatalysts

Understanding the fundamental principle of catalytic performance and the mechanism of multimetal-based electrocatalysts is essential for the rational design of advanced renewable energy systems. Here, the highly crystalline MMMoB4 (M=Fe,...

Boride-derived oxygen-evolution catalysts

Metal borides/borates have been considered promising as oxygen evolution reaction catalysts; however, to date, there is a dearth of evidence of long-term stability at practical current densities. Here we report a phase composition modulation approach to fabricate effective borides/borates-based catalysts. We find that metal borides in-situ formed metal borates are responsible for their high activity. This knowledge prompts us to synthesize NiFe-Boride, and to use it as a templating precursor to form an active NiFe-Borate catalyst. This boride-derived oxide catalyzes oxygen evolution with an overpotential of 167 mV at 10 mA/cm2 in 1 M KOH electrolyte and requires a record-low overpotential of 460 mV to maintain water splitting performance for over 400 h at current density of 1 A/cm2. We couple the catalyst with CO reduction in an alkaline membrane electrode assembly electrolyser, reporting stable C2H4 electrosynthesis at current density 200 mA/cm2 for over 80 h.

Theoretical Design of Novel Boron-Based Nanowires via Inverse Sandwich Clusters

Borophene has important application value, boron nanomaterials doped with transition metal have wondrous structures and chemical bonding. However, little attention was paid to the boron nanowires (NWs). Inspired by the novel metal boron clusters Ln2Bn− (Ln = La, Pr, Tb, n = 7–9) adopting inverse sandwich configuration, we examined Sc2B8 and Y2B8 clusters in such novel structure and found that they are the global minima and show good stability. Thus, based on the novel structural moiety and first-principles calculations, we connected the inverse sandwich clusters into one-dimensional (1D) nanowires by sharing B−B bridges between adjacent clusters, and the 1D-Sc4B24 and 1D-Y2B12 were reached after structural relaxation. The two nanowires were identified to be stable in thermodynamical, dynamical and thermal aspects. Both nanowires are nonmagnetic, the 1D-Sc4B24 NW is a direct-bandgap semiconductor, while the 1D-Y2B12 NW shows metallic feature. Our theoretical results revealed that the inverse sandwich structure is the most energy-favored configuration for transition metal borides Sc2B8 and Y2B8, and the inverse sandwich motif can be extended to 1D nanowires, providing useful guidance for designing novel boron-based nanowires with diverse electronic properties.