Electrocatalytic Performance of Metal Borides for Water Splitting

Metal borides have emerged as a compelling class of electrocatalysts for water splitting, simultaneously driving the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Their appeal stems from the combination of earth-abundant metal centres, strong metal–boron interactions and intrinsic electronic conductivity. Boron alters the d-band structure of transition metals, tuning hydrogen adsorption energies and facilitating multi-electron transfer at moderate overpotentials. Tailoring of crystallinity—from amorphous to layered diborides—enables optimisation of active sites and surface areas, while self-supported films and nanostructures address the need for robust electrode architectures. Recent advances have delivered bifunctional catalysts active across wide pH ranges and stable at practical current densities, bringing low-cost hydrogen production closer to industrial realisation. Critical challenges remain in controlling long-term durability under harsh electrolytic conditions and scaling synthesis routes. Overall, metal borides stand at the forefront of next-generation electrocatalysts poised to integrate with renewable electricity and contribute to a net-zero carbon economy.

Research from Nature Portfolio

Recent studies have explored atomic-level design of boride systems to attain record activity. Single-atom doping of cobalt selenide nanobelts with tailored ratios of metal–nitrogen to metal–selenium bonds has revealed a volcano-type dependence of HER activity on local coordination, yielding current densities of 10 mA cm−2 at under 100 mV in acidic media. In parallel, phase-composition modulation of nickel-iron borides has demonstrated that in situ conversion to borate-rich phases under OER conditions leads to overpotentials as low as 167 mV at 10 mA cm−2 and remarkable stability at 1 A cm−2 for hundreds of hours. Layered magnesium diboride doped with cobalt and iron has been shown to catalyse both HER and OER in alkaline electrolyte, with overpotentials near 470 mV for HER and overall water-splitting voltages approaching those of benchmark platinum/ruthenium pairs, highlighting the promise of doped MB2 phases as versatile bifunctional electrodes.

Electrocatalytic Performance of Metal Borides for Water Splitting publication trend

The graph below shows the total number of articles in electrocatalytic performance of metal borides for water splitting across all publications each year (not limited to Nature Index journals).

Technical terms

Electrocatalysis: Acceleration of redox reactions at electrode surfaces by a catalyst.

Hydrogen evolution reaction (HER): Reduction of protons to hydrogen gas at the cathode.

Oxygen evolution reaction (OER): Oxidation of water to oxygen gas at the anode.

Overpotential: Extra voltage beyond the thermodynamic potential required to drive an electrochemical reaction at a given rate.

Tafel slope: Parameter quantifying the change in overpotential per decade of current density, indicative of reaction kinetics.

Self-supported electrode: Catalytic film or architecture that adheres directly to a current collector without additional binders.

References

1. Metal Boride‐Based Catalysts for Electrochemical Water‐Splitting: A Review. Advanced Functional Materials (2019).
2. Dopant triggered atomic configuration activates water splitting to hydrogen. Nature Communications (2023).
3. Boride-derived oxygen-evolution catalysts. Nature Communications (2021).
4. Metal doped layered MgB2 nanoparticles as novel electrocatalysts for water splitting. Scientific Reports (2021).
5. Self‐supported thin‐film electrode consisting of transition metal borides for highly efficient hydrogen evolution. Carbon Energy (2024).
6. Exploring the Role of Multi-Catalytic Sites in an Amorphous Co–W–B Electrocatalyst for Hydrogen and Oxygen Evolution Reactions. ACS Applied Energy Materials (2023).
7. Structure-Induced Catalytic Activity of Nickel- and Cobalt-Substituted Layered MoB2 toward Hydrogen Evolution. ACS Sustainable Chemistry & Engineering (2022).