Microwave-assisted synthesis of iridium oxide and palladium nanoparticles supported on a nitrogen-rich covalent triazine framework as superior electrocatalysts for the hydrogen evolution and oxygen reduction reaction

Abstract

Iridium oxide (IrOx-NP) and palladium nanoparticles (Pd-NP) were supported on a 2,6-dicyanopyridine-based covalent-triazine framework (DCP-CTF) by energy-saving and sustainable microwave-assisted thermal decomposition reactions in propylene carbonate and in the ionic liquid [BMIm][NTf2]. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) confirm well-distributed NPs with sizes from 2 to 13 nm stabilized on the CTF particles. Metal contents between 10 and 41 wt% were determined by flame atomic absorption spectroscopy (AAS). Nitrogen sorption measurements of the metal-loaded CTFs revealed Brunauer–Emmett–Teller (BET) surface areas between 904 and 1353 m2 g−1. The composites show superior performance toward the hydrogen evolution reaction (HER) with low overpotentials from 47 to 325 mV and toward the oxygen reduction reaction (ORR) with high half-wave potentials between 810 and 872 mV. IrOx samples in particular show high performances toward HER while the Pd samples show better performance toward ORR. In both reactions, electrocatalysts can compete with the high performance of Pt/C. Exemplary cyclic voltammetry durability tests with 1000 cycles and subsequent TEM analyses show good long-term stability of the materials. The results demonstrate the promising synergistic effects of NP-decorated CTF materials, resulting in a high electrocatalytic activity and stability.

Emerging covalent triazine framework-based nanomaterials for electrochemical energy storage and conversion

“…In another work, Janiak et al deposited Pd and IrO x nanoparticles on an N-rich CTF using an energy-saving microwave route to drive the reaction. 206 The developed samples demonstrated similar electrocatalytic behavior toward the HER and ORR in comparison to 20% commercial Pt/C.…”

“…In another work, Janiak et al deposited Pd and IrO x nanoparticles on an N-rich CTF using an energy-saving microwave route to drive the reaction. 206 The developed samples demonstrated similar electrocatalytic behavior toward the HER and ORR in comparison to 20% commercial Pt/C. Furthermore, Liu et al prepared N-rich hollow carbon nanoflowers (N-HCNFs) from a preformed organic mesocrystal-CTF template by polymerization and subsequent carbonization.…”

Novel Microwave-Assisted Synthesis of COFs: 2020–2022

“…In fact, microwave-assisted thermal decomposition reactions of metal complexes are established methods for the synthesis of metal NPs. Palladium nanoparticles and iridium oxides have been prepared on 2,6-dicyanopyridine-based CTF (DCP-CTF) [ 53 ]. Either Pd(acac) 2 or Ir 4 (CO) 12 were dispersed with DCP-CTF and were irradiated at 100 W for 20 min (Pd-NP) or 30 min (IrOx-NP).…”

Microwave Encounters Ionic Liquid: Synergistic Mechanism, Synthesis and Emerging Applications

“…Besides, no additional stabilizers or capping molecules were needed. Apart from pure metal nanoparticles, they employed this MAIL method to fabricate alloy nanoparticles, including Cu-Zn alloy nanoparticles and Co-Al nanoparticles . In the above studies, the nanoparticles produced from the MAIL route were crystalline and showed no significant agglomerations.…”