Metal-free activation of molecular oxygen by covalent triazine frameworks for selective aerobic oxidation

Abstract

Oxygen activation is a critical step in ubiquitous heterogeneous oxidative processes, most prominently in catalysis, electrolysis, and pharmaceutical applications. We present here our findings on metal-free O2 activation on covalent triazine frameworks (CTFs) as an important class of N-rich materials. The O2 activation process was studied for the formation of aldehydes, ketones and imines. A detailed mechanistic study of O2 activation and the role of nitrogen heteroatoms were comprehensively investigated. The electron paramagnetic resonance (EPR) and control experiments provide strong evidence for the reaction mechanism proving the applicability of the CTFs to activate oxygen into superoxide species. This report highlights the importance of a self-templating procedure to introduce N functionalities for the development of metal-free catalytic materials. The presented findings reveal an important step toward the use of CTFs as inexpensive and high-performance alternatives to metal-based materials not only for catalysis but also for biorelated applications dealing with O2 activation.

Stable Unbiased Photo‐Electrochemical Overall Water Splitting Exceeding 3% Efficiency via Covalent Triazine Framework/Metal Oxide Hybrid Photoelectrodes

“…The bands ranging from 1200 to 1600 cm −1 correspond to the vibrations of triazine heterocycles in CTF-BTh whereas the peaks at 217, 417, 520, and 636 cm −1 originate from Cu 2 O (Figure S10, Supporting Information). [42,43] In Fourier transform-infrared (FTIR) spectra, the peaks at 600 and 638 cm −1 are ascribed to the vibrations of CuO bond and the characteristic peaks at 1380 and 1550 cm −1 can be assigned to the CN and CN groups in CTF-BTh (Figure S11, Supporting Information). [36,42] These characterizations unambiguously prove that the CTF-BTh thin film is formed on the surface of Cu 2 O.…”

Aromatic Dendrimers Bearing 2,4,6-Triphenyl-1,3,5-triazine Cores and Their Photocatalytic Performance

“…First, there are literature reports on the use of 1,3,5-triazine-containing polymers or materials in photocatalytic oxidation of primary amines. 37 − 44 We supposed that D2 might exhibit better catalytic performance than D1 because of above-discussed enhanced light-emission properties arising from the higher content of pyridinic nitrogen atoms. 38 Second, HOMO–LUMO band gaps estimated for D1 and D2 by the Tauc plot method 45 (3.5–3.6 eV; see Section S3 ) suggest that oxidation as well as electron transfer processes in the studied reaction should be feasible.…”

Cation-π induced surface cleavage of organic pollutants with ⋅OH formation from H2O for water treatment

“…As a result, the AOPs are rarely applied to eliminate organic pollutants at a large scale. Most of the organic pollutants possess very high chemical energy, but these reactant energies have not been effectively utilized for water purification (Li et al., 2015b; Abednatanzi et al., 2020 ). Cation-π interactions are electrostatic attractions between cations and electron-rich π orbitals ( Gebbie et al., 2017 ).…”