Electron‐deficient covalent organic frameworks anchored on melamine sponges for visible‐light‐driven H₂O₂ evolution

Abstract

A series of covalent organic frameworks (COFs) with β‐ketoenamine linkages named TpTt‐COF, TAPT‐COF, and TpPa‐1 were constructed for photocatalytic H2O2 generation in pure water and ambient air under visible light. Among them, TpTt‐COF performed striking H2O2 yield of 2647 μmol L−1, which is 3.5, 17.5, and 176.5‐fold those of TAPT‐COF, TpPa‐1, and bulk g‐C3N4, respectively, attributing to the electron‐deficient trait, short charge diffusion distance, and the narrowest bandgap of TpTt‐COF. Additionally, to achieve the facile recovery, TpTt‐COF was firmly and evenly anchored on melamine sponges (MS) because plenty of amino groups on the surface of MS could be involved in the β‐ketoenamine formation and guide the synthesis of TpTt‐COF on MS. The corresponding H2O2 evolution over this photocatalyst monolith is also respectable and can be well repeated at least four times. This work is quite instructive for photocatalyst construction based on covalent organic frameworks and facile photocatalytic applications.

Recent progress of biomass in conventional wood adhesives: a review

“…It is produced through the copolymerization of melamine, urea, and formaldehyde. 67–69 The water resistance of MUF resin can be enhanced by increasing the percentage of melamine used in the synthesis. This is due to the superior water resistance of the C–N bonds formed between the melamine ring and the methylene bridge, 70 compared with the C–N bonds in UF resin.…”

Defect-engineered Zr-MOFs with enhanced O2 adsorption and activation for photocatalytic H2O2 synthesis

“…H 2 O 2 is a green, versatile and high-energy oxidant, and has great application values in the fields of bleaching, pollutant removal and chemical synthesis. 1,2 Moreover, H 2 O 2 also has the ability to store hydrogen. 3 Under such a background, the global demand for H 2 O 2 will reach a staggering level in the next decades.…”

Efficient Photocatalytic Cleavage of C–C Bonds in β-1 Lignin Models and Aromatic Vicinal Diols by Combining Alkali Metal-Treated Graphitic Carbon Nitride and Persulfate

“…β-1 lignin models such as 1,2-diphenylethanol (Dpol) are often used as substrates to study the cleavage process of lignin C–C bonds. − However, previous studies often require the addition of expensive oxidants or bases to the catalytic system. , High temperatures and pressures also seem to be necessary to break lignin C–C bonds. , Therefore, the development of green and sustainable technologies to break lignin C–C bonds is very attractive to promote the high-value utilization of lignin. Nowadays, photocatalytic technology has been rapidly developed. − Photocatalytic production of hydrogen peroxide, − photocatalytic CO 2 reduction to methanol, and photocatalytic environmental treatment have been widely studied. In the past 5 years, photocatalytic techniques have also been used to break the C–C bonds in lignin models (Dpol and 2-phenoxy-1-phenylethanol, PPol) and organosolv lignin. , However, the low photocatalytic efficiency became a bottleneck for breaking the lignin C–C bonds.…”