An Iron-Group Metal Boride/Boron-Doped Vertically Oriented Graphene as Efficient Catalyst for Overall Water Splitting in a Wide pH Range

Abstract

Exploring earth-abundant and non-noble metal bifunctional stable electrocatalysts with excellent catalytic performance for overall water splitting in a wide pH range is greatly desirable and challenging. Herein, a newly designed Fe-Co-Ni-B/boron−doped vertically oriented graphene (Fe-Co-Ni-B/BVG) electrocatalyst is fabricated via single−step electrodeposition method. The as-synthesized electrocatalyst exhibits excellent hydrogen evolution reaction (HER) activities with low overpotentials of 41, 140, and 168 mV at a current density of 10 mA cm −2 in 1.0 M KOH, 0.5 M H 2 SO 4 , and 1.0 M phosphate buffer solutions (PBS), respectively at all pH values (pH 0-13.8). Fe-Co-Ni-B/BVG electrocatalyst also exhibits excellent oxygen evolution reaction (OER) activities with overpotentials of 163 and 110 mV at a current density of 10 mA cm −2 in 1.0 M KOH and 1.0 M PBS solutions, respectively. This electrocatalyst also shows prominent electrochemical durability (over more than 10 h). This study may provide a facile design for the fabrication of cost-effective and non-noble metal bifunctional electrocatalysts material for overall water splitting withstand in different pH conditions.

FeCoNiS Nanoparticles Integrated with Nitrogen−Doped Vertically Oriented Graphene via Single−Step Electrodeposition: An Efficient Bifunctional Catalyst for Overall Water Splitting

“…Preparing vertically oriented graphene (VG) is an efficient approach to overcome this issue. 34,35 FeCoNiS/NVG (N-doped vertically oriented graphene) is synthesized via single-step electrodeposition. FeCoNiS/NVG exhibits excellent catalytic performance for HER and OER owing to higher active surface area, more active sites and highly conductive structure.…”

Fe/Ni-Doped Co5.47N Nanoparticles Integrated on Nitrogen-Doped Vertical Reduced Graphene Oxide Arrays for Overall Water Splitting in Wide pH Range

“…Moreover, N-doped VrGO has been further demonstrated to improve the electrolytic water performance of the catalyst better than other heteroatoms (S, P, B)-doped VrGO. 24,25 Further, iron group metal borides loaded on B-VrGO, 26 iron group metal phosphides loaded on P-VrGO, 27 and iron group metal sulfides loaded on S-VrGO have been shown in our previous work to have significantly improved the electrocatalytic performances of iron group metal compounds. For example, FeCoNiP@P-rGO has been shown to have significantly higher electrocatalytic properties than other heteroatom-doped rGO integrated catalysts attributed to the synergy between the P in P-rGO and FeCoNiP.…”

Higher Water‐Splitting Performance of Boron‐Based Porous CoMnB Electrocatalyst over the Benchmarks at High Current in 1 m KOH and Real Sea Water

“…[25] In the CoMnB configuration, the metallic atoms such as Co and Mn may accept the electrons from the B atoms in the ionic bonding based on the superior electron transfer nature of B atoms. [14,22] The electron-enriched active sites can effectively lower the reaction barrier for the HOH bond breaking and facilitate the absorption of H + and OH − ions, resulting in improved HER and OER performances along with the increased incorporation of B atoms. In addition, the porous design provides more exposed active sites and can guarantee the full contact between electrolytes and the surface of CoMnB catalysts, which is beneficial for the redox reaction.…”

“…Electrochemical Measurements: The electrochemical analyses were performed by an electrochemical workstation in a 1.0 m KOH solution. The potential (E) conversion of reversible hydrogen electrode (RHE) was based on the following relation: E [V vs RHE] = E + 0.1971(Ag/ AgCl) + 0.059 × pH (14) with a three-electrode (3-E) configuration. The LSV was utilized to measure the polarization curves at the scan rate of 5 mV s −1 .…”

“…[1] With the high gravimetric energy density and zero-carbon the water electrocatalysts with the efficient electron transfer capability and orbital alternating nature in the transition metal matrix with the multicentered bonding characteristics. [13][14][15][16] The transferred electrons from the B atoms can be ionically combined into the d-orbitals of transition metal atoms to form an electron-enriched catalytic surface, resulting in the improved adsorption of hydroxyl functional groups and hydrogen protons and thus can significantly enhance the H 2 and O 2 generation process. At the same time, the boron in the transition metals can stabilize the atomic hybridization and can offer the improved stability of electrocatalysts.…”