Molecularly Engineered Covalent Organic Frameworks for Hydrogen Peroxide Photosynthesis

Abstract

Synthesizing H2O2 from water and air via a photocatalytic approach is ideal for efficient production of this chemical at small‐scale. However, the poor activity and selectivity of the 2 e− water oxidation reaction (WOR) greatly restricts the efficiency of photocatalytic H2O2 production. Herein we prepare a bipyridine‐based covalent organic framework photocatalyst (denoted as COF‐TfpBpy) for H2O2 production from water and air. The solar‐to‐chemical conversion (SCC) efficiency at 298 K and 333 K is 0.57 % and 1.08 %, respectively, which are higher than the current reported highest value. The resulting H2O2 solution is capable of degrading pollutants. A mechanistic study revealed that the excellent photocatalytic activity of COF‐TfpBpy is due to the protonation of bipyridine monomer, which promotes the rate‐determining reaction (2 e− WOR) and then enhances Yeager‐type oxygen adsorption to accelerate 2 e− one‐step oxygen reduction. This work demonstrates, for the first time, the COF‐catalyzed photosynthesis of H2O2 from water and air; and paves the way for wastewater treatment using photocatalytic H2O2 solution.

Enhanced H2O2 Production via Photocatalytic O2 Reduction over Structurally-Modified Poly(heptazine imide)

“…The solar-to-chemical conversion (SCC) efficiency 50 for H 2 O 2 production from H 2 O and O 2 (2H 2 O + O 2 + h ν → 2H 2 O 2 : Δ G ° = 117 kJ mol –1 ) (i.e., in the absence of a sacrificial agent) was determined using the same reaction setup used for other particulate photochemical experiments as discussed in previous sections. In a typical photochemical 7.5 mg of MX → PHI photocatalyst was dispersed in 7.5 mL of DIW.…”

Edge- and bridge-engineering-mediated exciton dissociation and charge separation in carbon nitride to boost photocatalytic H2 evolution integrated with selective amine oxidation

“…49 In addition, the two peaks at 106.6 and 114.5 ppm can be ascribed to the CC bond. 50 Therefore, the structural characterization confirmed that EBCN-2 has the desired structure. In addition, the corresponding edge sites (ECN) and bridge sites (BCN) of C 3 N 4 were prepared, and their detailed structural information is discussed in ESI (Fig.…”

Metalated covalent organic frameworks: from synthetic strategies to diverse applications

“…Briefly, post-synthetic metalation is a general and versatile method for 2,2′-bipyridine-COF metalation that has been widely used for the synthesis of metalated 2,2′-bipyridine-COFs, as summarized in Table 2. 136,141,146,229–254…”