Nickel Glyoximate Based Metal–Covalent Organic Frameworks for Efficient Photocatalytic Hydrogen Evolution

Abstract

Metal-covalent organic frameworks (MCOFs) have been recently received wide attention owing to the homogeneous distribution of active metal centers that are beneficial for enhancing the application potentials. However, metal complex based functional building blocks for MCOFs synthesis are limited. Herein, two new MCOFs (Ni-Py-COF and Ni-Bn-COF) were constructed via a novel nickel glyoximate based building block. Splendid photocatalytic activity on hydrogen evolution from water and great long-term recyclability were achieved using these nickel glyoximate based MCOFs as photocatalysts. Excitingly, even without the addition of Pt co-catalyst, the hydrogen evolution rates (HER) of Ni-Py-COF reached up to 626 μmol g À 1 h À 1 , which is better than many porous organic polymers. This work not only expands the type of building units for MCOFs, but also provides meaningful insights for developing stable, efficient and earth-abundant photocatalysts toward H 2 generation.Covalent organic frameworks (COFs), as a promising class of porous crystalline polymers, have demonstrated considerable advantages and application potential in various fields owing to designable structures and tailor-made functions. [1] C, H, N and other light elements constituted the majority of COFs namely metal-free COFs. [2] However, most metal-free COFs fail to exhibit versatile and outstanding properties due to their limited constituent elements. [3] Recently, a new class of COFs with intentionally integrated metal centers into the skeletons are considered as promising candidates to address this dilemma; these are referred to as metal-covalent organic frameworks (MCOFs). [4] MCOFs not only inherit

A thiazolo[5,4-d]thiazole functionalized covalent triazine framework showing superior photocatalytic activity for hydrogen production and dye degradation

“…This conclusion is also consistent with our experimental results. 78 The results of the LSV for CTF-NWU-1 and CTF-NWU-2 photocatalysts are shown in Fig. 5c.…”

Reconstruction of Highly Dense Cu−N4Active Sites in Electrocatalytic Oxygen Reduction Characterized by Operando Synchrotron Radiation

“…Exploration and utilization of green energy is essential to achieve the goal of carbon neutrality and emission peak. [1][2][3] Hydrogen energy is a clean energy that can store waste energy and promote the transformation from traditional fossil energy to green energy. Its energy density (140 MJ kg À 1 ) is 3 times of petroleum and 4.5 times of coal, which is regarded as a disruptive technology direction of future energy revolution.…”

Integrating Light‐Harvesting Ruthenium(II)‐based Units into Three‐Dimensional Metal Covalent Organic Frameworks for Photocatalytic Hydrogen Evolution

“…The higher performance of RuCOF-TPB as compared to the other two materials could be ascribed to the cumulative effect of its broader light absorption range (Figure 4a), more efficient photoinduced electron-hole separation (Figures 4c and S46), and higher hydrophilicity (Figure S47). Noteworthily, the HER activity of RuCOF-TPB is far superior to most of the reported MCOFs and COFs (Table S2), such as NiÀ BnÀ COF [25] (1805 μmol g À 1 h À 1 ), sp 2 c-COF [41] (1360 μmol g À 1 h À 1 ) and COF-DFB [42] (2120 μmol g À 1 h À 1 ). Moreover, the apparent quantum efficiency of RuCOF-TPB measuring at 420 nm was 6.95 %, which is also higher than most of the reported COF-based photocatalysts (Table S2).…”