Phyto-inspired and scalable approach for the synthesis of PdO–2Mn₂O₃: a nano-material for application in water splitting electro-catalysis

Abstract

A modified co-precipitation method has been used for the synthesis of PdO–2Mn2O3 nanocomposite as an efficient electrode material for the electro-catalytic oxygen evolution (OER) and hydrogen evolution reaction (HER).

Functionalization of Mn 2 O 3 / PdO / ZnO electrocatalyst using organic template with accentuated electrochemical potential toward water splitting

“…Although the electrochemical potential of the synthesized material is excellent comparative to the discussed chemically synthesized material, but still this potential could be improved further by varying the parameters, for example, molar concentration of each precursor with the extract, temperature variation, and also by varying the electrolyte or electrolyte concentration. As in one of our previous work 53 in which bio‐fabricated PdO‐2Mn 2 O 3 /Ni‐foam has been used as electrode material, the obtained overpotential value was 359 mV@10 mA/cm 2 . In another study by Zahra et al 52 prepared an efficient hybrid ZnO/Mn 3 O 4 OER nanocatalyst by biomimetic approach with an overpotential value of 420 mV which is closer to the currently synthesized ternary composite at 10 mA/cm 2 current density.…”

“…Using Tauc's plot the optical band gap of bio‐fabricated Mn 2 O 3 /PdO/ZnO was calculated as represented in Equation () below: From the above equation the calculated optical band energy for Mn 2 O 3 /PdO/ZnO Nps is 2.2 eV which is ideal for water splitting application as 1.23 eV energy is required to accelerate the reaction 65 and the narrowing of the band energy could enhance the light absorption properties of the material. In one of our previous work, 53 in which phytocapped PdO‐2Mn 2 O 3 exhibited a band gap value of 3.18 eV. In the current investigation with the addition of ZnO (Mn 2 O 3 /PdO/ZnO) the band gap energy is reduced to 2.2 eV with the difference of 0.98 eV.…”

“…All impedance measurements were recorded at frequency range of 0.05 Hz to 10 kHz in an applied AC amplitude of 10 mV. The potential was changed to RHE by applying Nernst equation 53,55 …”

“…Plant leaves are considered as the major source of metabolites owing to their regrowth in comparison to other tissues that is why in the current study foliar extract has been opted for synthesis of nanoparticles. Olea ferruginea royle has been used as a source of organic compounds in our previous studies 52‐54 and has essential organic compounds that can be used as fuel for the synthesis of nanomaterials of metal oxides, such as octodrine, alanine, cyclobutanol, etc. The reported literature on bio‐synthesis is narrowed to only mono‐metallic oxides with very little or no literature on binary, ternary, doped or composite oxides.…”

Electrocatalytic Oxidation of Water by OH−‐ and H2O‐Capped IrOx Nanoparticles Electrophoretically Deposited on Graphite and Basal Plane HOPG: Effect of the Substrate Electrode**

“…Such correlations and dependencies were observed not only for the IrO x NPs, but also for other electrocatalytic NPs. [32,33] For example, Zahra et al [32] showed that the presence of organic phyto-compounds or carbon-containing capping agents used in the synthesis of the PdO-2Mn 2 O 3 improves the catalytic efficiency of this electrocatalyst toward OER.…”