Metal doped layered MgB2 nanoparticles as novel electrocatalysts for water splitting

Abstract

Growing environmental problems along with the galloping rate of population growth have raised an unprecedented challenge to look for an ever-lasting alternative source of energy for fossil fuels. The eternal quest for sustainable energy production strategies has culminated in the electrocatalytic water splitting process integrated with renewable energy resources. The successful accomplishment of this process is thoroughly subject to competent, earth-abundant, and low-cost electrocatalysts to drive the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), preferably, in the same electrolyte. The present contribution has been dedicated to studying the synthesis, characterization, and electrochemical properties of newfangled electrocatalysts with the formal composition of Mg1−xTMxB2 (x = 0.025, 0.05, and 0.1; TM (transition metal) = Fe and Co) primarily in HER as well as OER under 1 M KOH medium. The electrochemical tests revealed that among all the metal-doped MgB2 catalysts, Mg0.95Co0.05B2 has the best HER performance showing an overpotential of 470 mV at − 10 mA cm−2 and a Tafel slope of 80 mV dec−1 on account of its high purity and fast electron transport. Further investigation shed some light on the fact that Fe concentration and overpotential for HER have adverse relation meaning that the highest amount of Fe doping (x = 0.1) displayed the lowest overpotential. This contribution introduces not only highly competent electrocatalysts composed of low-cost precursors for the water-splitting process but also a facile scalable method for the assembly of highly porous electrodes paving the way for further stunning developments in the field.

Microwave-Assisted Auto-Combustion Synthesis of Binary/Ternary CoxNi1−xFerrite for Electrochemical Hydrogen and Oxygen Evolution

“…From Figure b , calculated Tafel slopes can be seen. The Tafel slope is a key indicator to ascertain the HER kinetics, establishing the rate-controlling step during the reaction. , The two general routes reported in the literature − for hydrogen evolution under basic conditions are as follows …”

Tailoring the Morphology of Cost-Effective Vanadium Diboride Through Cobalt Substitution for Highly Efficient Alkaline Water Oxidation

“…In general nitrides, phosphides, carbides, sulfides, oxides, and borides of TMs are under thorough scrutiny. ,, In particular, TM borides (TMBs) based on elements of Co, Ni, Fe, and Mo have been identified as favorable catalysts toward OER under alkaline media, revealing better performance and tolerance compared to those of precious metal-based ones. ,,− TMBs, containing electron-deficient boron, have attracted tremendous attention owing to their exotic mechanical and electrical properties. As a new family included in the electrocatalysis library, TMBs possess high hardness, excellent thermal stability, oxidation resistance, and favorable electronic transport characteristics, on account of their intrinsic M–M, M–B, and B–B bonding attributes. ,− Considering the abovementioned merits, TMBsamorphous and crystallineare considered as potential bifunctional catalysts as well . Metal diborides (MDbs), a subgroup of the large family of TMBs, have very recently come into the picture for HER due to their higher electronic conductivity and density of active sites. , Despite considerable signs of progress achieved in catalytic properties of MDbs toward HER, − their electrocatalytic activities toward OER remained largely unknown.…”

“…Lately, our group explored layered MgB 2 and ZrB 2 MDbs as potential materials for both HER and OER. , Inspired by encouraging results, we report electrocatalytic features of layered metallic vanadium diboride (VB 2 ) for OER. VB 2 adopts the hexagonal AlB 2 structure type with the space group P 6 / mmm .…”

Design of metal‐substituted tungsten diboride as an efficient bifunctional electrocatalyst for hydrogen and oxygen evolution

“…Identical to our earlier reports 20,[28][29][30] and similar to the molten salt technique, all the preparation, weighing, and transferring of the precursors into the stainless-steel vial were conducted in an Ar-filled glovebox. The powder precursor was mechanically activated for 180 minutes at 1200 rpm.…”

“…6,28 Thus far, we have investigated the role of several TMs (Fe, Co, Ni, and Cu) in the structure of AlB 2 -type MDbs (MgB 2 , ZrB 2 , VB 2 , and HfB 2 ) for the alkaline electrolysis of HER and OER. 20,[28][29][30] On the basis of experimental studies, it was concluded that Co-and Ni-bearing materials are superior electrocatalysts as opposed to Fe-and Cu-bearing counterparts. Inspired by the earlier investigations and encouraged by our recent research on the various MDbs, herein, we present the electrochemical attributes of W (1-x) TM x B 2 (TM = Ni and Co; x = 0, 0.1, 0.2, and 0.3) toward OER and HER.…”