Nickel nanoparticles supported on a covalent triazine framework as electrocatalyst for oxygen evolution reaction and oxygen reduction reactions

Abstract

Covalent triazine frameworks (CTFs) are little investigated, albeit they are promising candidates for electrocatalysis, especially for the oxygen evolution reaction (OER). In this work, nickel nanoparticles (from Ni(COD)2) were supported on CTF-1 materials, which were synthesized from 1,4-dicyanobenzene at 400 °C and 600 °C by the ionothermal method. CTF-1-600 and Ni/CTF-1-600 show high catalytic activity towards OER and a clear activity for the electrochemical oxygen reduction reaction (ORR). Ni/CTF-1-600 requires 374 mV overpotential in OER to reach 10 mA/cm2, which outperforms the benchmark RuO2 catalyst, which requires 403 mV under the same conditions. Ni/CTF-1-600 displays an OER catalytic activity comparable with many nickel-based electrocatalysts and is a potential candidate for OER. The same Ni/CTF-1-600 material shows a half-wave potential of 0.775 V for ORR, which is slightly lower than that of commercial Pt/C (0.890 V). Additionally, after accelerated durability tests of 2000 cycles, the material showed only a slight decrease in activity towards both OER and ORR, demonstrating its superior stability.

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

“…Furthermore, the comparison of the measured half-wave potentials for the different metal species results in a similar trend as in the literature for Pt, Pd, and Ir (Rahman et al, 2021). For Pt 20 /C a current density of 2.8 mA cm −2 and a half-wave potential of 884 mV could be measured in the 1.0 mol L −1 KOH electrolyte, which is comparable to the literature (Yan et al, 2015;Öztürk et al, 2020). Note that the current density is strongly influenced by the concentration of the electrolyte.…”

Covalent Triazine Frameworks Based on the First Pseudo-Octahedral Hexanitrile Monomer via Nitrile Trimerization: Synthesis, Porosity, and CO2 Gas Sorption Properties

“…Additionally, the IR spectra show the characteristic C-N stretching and breathing modes for triazine units at around 1500 and 1360 cm −1 as well as the breathing modes for the triazine unit at around 810 cm −1 (Figure 1 for CTF-hex6 and Supplementary Information Figures S1-S3 for CTF-hex1-5, green). Simultaneously, the intense IR bands for the nitrile group at around 2230 cm −1 decreased significantly compared to the starting material (Figure 1 for CTF-hex6 and Supplementary Information Figures S1-S3 for CTF-hex1-5, red) [27,43,46,68]. These observations prove a successful polymerization, but the presence of the nitrile signal indicates an incomplete conversion and supports the results of the elemental analysis again.…”

“…As expected, the percentage of nitrogen of the triazine framework CTF-hex6 synthesized under ionothermal reaction conditions is the lowest compared to the synthesized frameworks CTF-hex1-5 due to more defects and more significant decomposition at higher temperatures [25,29,67]. The structure of CTFs from ionothermal reactions with ZnCl 2 approaches those of porous carbon materials, especially at temperatures above 400 • C, where a significant amount of nitrogen is lost, such that these CTFs may be better described as nitrogen-doped porous carbon [14,29,34,68]. On the other hand, TFMS-catalysed CTFs usually approach the idealized structure [29].…”

Nickel-Based Metal-Organic Frameworks as Electrocatalysts for the Oxygen Evolution Reaction (OER)

“…The depletion of fossil fuels and their direct correlation in increasing global greenhouse gas emissions through their combustion show that the development of new sustainable clean energy sources is required [1][2][3]. A possible solution is coupling renewable energy sources like solar and wind energy with electrochemical water splitting to convert surplus electrical energy into storable hydrogen fuel [4][5][6][7].…”