Hydrazine oxidation in single-atom catalysts (SACs) could exploit the efficiency of metal atom utilization, which is a substitution for noble metal-based electrolysers that results in reduced overall cost. A well-established ruthenium single atom over mesoporous carbon nitride (SRu-mC3N4) catalyst is explored for the electro-oxidation of hydrazine as one of the model reactions for direct fuel cell reactions. The electrochemical activity observed with linear sweep voltammetry (LSV) confirmed that SRu-mC3N4 shows an ultra-low onset potential of 0.88 V vs. RHE, and with a current density of 10 mA/cm2 the observed potential was 1.19 V vs. RHE, compared with mesoporous carbon nitride (mC3N4) (1.77 V vs. RHE). Electrochemical impedance spectroscopy (EIS) and chronoamperometry (i-t) studies on SRu-mC3N4 show a smaller charge-transfer resistance (RCt) of 2950 Ω and long-term potential, as well as current stability of 50 h and 20 mA/cm2, respectively. Herein, an efficient and enhanced activity toward HzOR was demonstrated on SRu-mC3N4 from its synergistic platform over highly porous C3N4, possessing large and independent active sites, and improving the subsequent large-scale reaction.
To produce clean and sustainable hydrogen energy through water electrolysis, the sluggish oxygen evolution reaction (OER) needs to be accelerated sustainably by using stable and highly effective electrocatalysts. Bimetallic nanocomposites have been recently recognized as an interesting class of electrocatalysts because of their synergistic behaviour, tunable morphology, and high catalytic efficiency. Herein, InC, AgC, and InAgC nanocomposites were synthesised via a hydrothermal method using a mesoporous carbon support derived from the carbonisation of giant cane. The structural characterisation revealed that the InC composite has tetragonal In with a minor presence of cubic In2O3, whereas AgC and InAgC are well aligned with cubic Ag and tetragonal In. Electron microscopy revealed that InC has a 3D plate-like structure, while InAgC exhibits a spherical shape and is uniformly dispersed across the carbon surface. InAgC showed excellent activity and durability for the OER, with a notably low overpotential of 480 mV at a current density of 100 mA cm−2, a Tafel slope of 97 mV dec−1, and an oxygen production turnover frequency of 10.19 s−1. The chronoamperometric (i–t) study of InAgC at 1.58 V vs. RHE for 20 h in 1 M KOH indicates that the catalyst is highly stable for the OER in alkaline electrolytes. The electrochemical double-layer capacitance (Cdl) value in the non-faradaic potential region of InAgC is greater (52.14 mF cm−2) than those of mesoporous carbon (16.54 mF cm−2), AgC (33.10 mF cm−2), and InC (48.77 mF cm−2), which is attributed to InAgC having more accessible active sites for the OER. This work presents numerous possibilities for developing effective nanocomposites using giant cane as a natural carbon source.
An efficient approach for the synthesis of medicinally important dihydropyrano[2,3- c ]pyrazoles derivatives by using Fe 3 O 4 @BTC nanocomposite (NCs) based catalytic system.