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Investigations into the selective oxidation of inert sp3 C−H bonds using polymer photocatalysts under mild conditions have been limited. Additionally, the structure‐activity relationship of photocatalysts often remains insufficiently explored. Here, a series of thiophene‐based covalent triazine frameworks (CTFs) are used for the efficient and selective oxidation of hydrocarbons to aldehydes or ketones under ambient aerobic conditions. Spectroscopic methods conducted in situ and density functional theory (DFT) calculations revealed that the sulfur atoms within the thiophene units play a pivotal role as oxidation sites due to the generation of photogenerated holes. The effect of photogenerated holes on photocatalytic toluene oxidation was investigated by varying the length of the spacer in a CTF donor‐acceptor based photocatalyst. Furthermore, the manipulation of reactive oxygen species was employed to enhance selectivity by weakening the peroxidative capacity. As an illustrative example, this study successfully demonstrated the synthesis of a precursor of the neurological drug AMG‐579 using a photocatalytic protocol. [ABSTRACT FROM AUTHOR]

Electrochemical two‐electron water oxidation (2e WOR) is gaining surging research traction for sustainable hydrogen peroxide production. However, the strong oxidizing environment and thermodynamically competitive side‐reaction (4e WOR) posit as thresholds for the 2e WOR. We herein report a custom‐crafted covalent triazine network possessing strong oxidizing properties as a proof‐of‐concept metal‐free functional organic network electrocatalyst for catalyzing 2e WOR. As the first‐of‐its‐kind, the material shows a maximum of 89.9 % Faradaic Efficiency and 1428 μmol/h/cm2 H2O2 production rate at 3.0 V bias potential (vs reversible hydrogen electrode, RHE), which are either better or comparable to the state‐of‐the‐art electrocatalysts. We have experimentally confirmed a stepwise 2e WOR mechanism which was further computationally endorsed by density functional theory studies. [ABSTRACT FROM AUTHOR]

Electrochemical two‐electron water oxidation (2e WOR) is gaining surging research traction for sustainable hydrogen peroxide production. However, the strong oxidizing environment and thermodynamically competitive side‐reaction (4e WOR) posit as thresholds for the 2e WOR. We herein report a custom‐crafted covalent triazine network possessing strong oxidizing properties as a proof‐of‐concept metal‐free functional organic network electrocatalyst for catalyzing 2e WOR. As the first‐of‐its‐kind, the material shows a maximum of 89.9 % Faradaic Efficiency and 1428 μmol/h/cm2 H2O2 production rate at 3.0 V bias potential (vs reversible hydrogen electrode, RHE), which are either better or comparable to the state‐of‐the‐art electrocatalysts. We have experimentally confirmed a stepwise 2e WOR mechanism which was further computationally endorsed by density functional theory studies. [ABSTRACT FROM AUTHOR]

Electrochemical two‐electron water oxidation (2e WOR) is gaining surging research traction for sustainable hydrogen peroxide production. However, the strong oxidizing environment and thermodynamically competitive side‐reaction (4e WOR) posit as thresholds for the 2e WOR. We herein report a custom‐crafted covalent triazine network possessing strong oxidizing properties as a proof‐of‐concept metal‐free functional organic network electrocatalyst for catalyzing 2e WOR. As the first‐of‐its‐kind, the material shows a maximum of 89.9 % Faradaic Efficiency and 1428 μmol/h/cm2 H2O2 production rate at 3.0 V bias potential (vs reversible hydrogen electrode, RHE), which are either better or comparable to the state‐of‐the‐art electrocatalysts. We have experimentally confirmed a stepwise 2e WOR mechanism which was further computationally endorsed by density functional theory studies. [ABSTRACT FROM AUTHOR]

Electrochemical two‐electron water oxidation (2e WOR) is gaining surging research traction for sustainable hydrogen peroxide production. However, the strong oxidizing environment and thermodynamically competitive side‐reaction (4e WOR) posit as thresholds for the 2e WOR. We herein report a custom‐crafted covalent triazine network possessing strong oxidizing properties as a proof‐of‐concept metal‐free functional organic network electrocatalyst for catalyzing 2e WOR. As the first‐of‐its‐kind, the material shows a maximum of 89.9 % Faradaic Efficiency and 1428 μmol/h/cm2 H2O2 production rate at 3.0 V bias potential (vs reversible hydrogen electrode, RHE), which are either better or comparable to the state‐of‐the‐art electrocatalysts. We have experimentally confirmed a stepwise 2e WOR mechanism which was further computationally endorsed by density functional theory studies. [ABSTRACT FROM AUTHOR]

Scalable and eco‐friendly synthesis of crystalline porous covalent triazine frameworks (CTFs) is essential to realize their broad industrial applications but remains a great challenge, which requires the fundamental understanding of the two‐dimensional polymerization mechanism. Herein, we report a universal polyphosphoric acid (H6P4O13)‐catalyzed nitrile trimerization route to synthesize a series of highly crystalline CTFs with high specific surface areas. This new strategy enables the cost‐effective large‐scale fabrication of crystalline CTFs at kilogram level for the first time. Through density functional theory calculation and detailed controlled experiments, we reveal that the polyphosphate acid show much higher catalytic activity for trimerization reaction than its analogues such as P2O5 and H3PO4. Furthermore, the crystalline CTFs with regular porosity and abundant triazine groups exhibit ultrahigh removal efficiency of micropollutants, indicating its great potential in environment remediation. [ABSTRACT FROM AUTHOR]

A template-free pyrolysis approach is proposed to fabricate nitrogen and sulfur doped hollow mesoporous carbon sphere (N/S-HMCS). The unique hollow/mesoporous nanostructure and abundant N, S-doped active sites prompt the optimal N/S-HMCS 900 exhibits satisfactory electrocatalysis in oxygen electroreduction for high-performance Zn-air battery. [Display omitted] • A nitrogen, sulfur dual-doped hollow mesoporous carbon sphere (N/S-HMCS) is fabricated by a simple yet efficient template-free pyrolysis approach. • The N/S-HMCS 900 exhibits high oxygen reduction reaction (ORR) activities with an excellent half-wave potential and high methanol tolerance. • The optimal electrocatalyst can be used as air electrode materials in high-performance zinc-air batteries. • Density functional theory (DFT) calculations reveal that N, S-dual dopant can create extra active sites with higher catalytic activity than the isolated N -dopant. The construction of hollow mesoporous carbon nanospheres (HMCS) avoiding the use of traditional soft/hard templates is highly desired for nanoscience yet challenging. Herein, we report a simple and straightforward template-free strategy for preparing nitrogen, sulfur dual-doped HMCSs (N/S-HMCSs) as oxygen reduction reaction (ORR) electrocatalysts. The unique hollow spherical and mesoporous structure was in-situ formed via a thermally initiated hollowing pathway from an elaborately engineered covalent triazine framework. Regulation of pyrolysis temperatures contributed to precisely tailoring of the shell thickness of HMCSs. The resulting N/S-HMCS 900 (pyrolyzed at 900 °C) possessed high N and S contents, large specific surface areas, rich and uniform mesopores distribution. Consequently, as a metal-free ORR electrocatalyst, N/S-HMCS 900 exhibits a high half-wave potential, excellent methanol tolerance and great long-term durability. Additionally, density functional theory calculations demonstrate that N, S-dual dopant can create extra active sites with higher catalytic activity than the isolated N -dopant. This strategy provides new insights into the construction of hollow and mesoporous multi-heteroatom-doped carbon materials with tunable nanoarchitecture for various electrochemical applications. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Post-metalation of a bipyridine-based CTF with an Ir(I) complex for C H borylation. • DFT calculations elucidated the local geometry in the Ir(I)@bipyCTF catalyst. • Ir(I)@bipyCTF outperforms the conventional iridium-based heterogeneous catalysts. Abstract Metal-modified covalent triazine frameworks (CTFs) have attracted considerable attention in heterogeneous catalysis due to their strong nitrogen-metal interactions exhibiting superior activity, stability and hence recyclability. Herein, we report on a post-metalation of a bipyridine-based CTFs with an Ir(I) complex for C H borylation of aromatic compounds. Physical characterization of the Ir(I)-based bipyCTF catalyst in combination with density functional theory (DFT) calculations exhibit a high stabilization energy of the Ir-bipy moiety in the frameworks in the presence of B 2 Pin 2. By using B 2 Pin 2 as a boron source, Ir(I)@bipyCTF efficiently catalyzed the C H borylation of various aromatic compounds with excellent activity and good recyclability. In addition, XAS analysis of the Ir(I)@bipyCTF gave clear evidence for the coordination environment of the Ir. [ABSTRACT FROM AUTHOR]

Herein, we report the first work on pyrolysis–free synthesis of robust conjugated metallophthalocyanine–based covalent triazine frameworks (MPc–CTF, M= Co, Ni) for pH-universal electrocatalytic CO 2 reduction reaction (CO 2 RR). CoPc–CTF shows high CO Faradaic efficiency over 94%, and long-term stability over 10 h in full pH range, and industry level CO partial current densities of 378.8 mA cm−2, 165.9 mA cm−2, 172.5 mA cm−2 in alkaline, neutral and acidic electrolytes, respectively. Particularly, the CO 2 utilization efficiency reaches 51.3% in acidic electrolytes. Moreover, operando characterizations and density functional theory calculations indicate the promoting effect of triazine moiety in CoPc–CTF to accelerate the formation of *COOH intermediates during CO 2 RR. This work provides an encouraging direction for designing robust conjugated network supported single site catalysts to access high product selectivity and high carbon utilization efficiency in electrocatalytic CO 2 reduction reaction. [Display omitted] • Robust metallophthalocyanine–based covalent triazine frameworks (CTFs) are prepared by a facile trimerization reaction. • CoPc–CTF shows superior CO 2 electrocatalytic performance in pH-universal electrolytes. • CoPc–CTF exhibits high J CO of 172.5, 378.8 mA cm–2 in acidic, and alkaline electrolyte, respectively. • The CO 2 utilization efficiency reaches 51.3% in acidic electrolyte. • The mechanism of electrocatalytic CO 2 reduction has been investigated. [ABSTRACT FROM AUTHOR]