Organic Molecule Bifunctionalized Polymeric Carbon Nitride for Enhanced Photocatalytic Hydrogen Peroxide Production

Abstract

Modifying the polymeric carbon nitride (CN) with organic molecules is a promising strategy to enhance the photocatalytic activity. However, most previously reported works show that interchain embedding and edge grafting of the organic molecule can hardly be achieved simultaneously. Herein, we successfully synthesized organic molecule bifunctionalized CN (MBCN) through copolymerization of melon and sulfanilamide at a purposely elevated temperature of 550 °C. In MBCN, the edge grafted and interchain embedded benzene rings act as the electron‐donating group and charge‐transfer channel, respectively, rendering efficient photocatalytic H2O2 production. The optimal MBCN exhibits a significantly improved non‐sacrificial photocatalytic H2O2 generation rate (54.0 μmol g–1 h–1) from pure water, which is 10.4 times that of pristine CN. Experimental and density functional theory (DFT) calculation results reveal that the enhanced H2O2 production activity of MBCN is mainly attributed to the improved photogenerated charge separation/transfer and decreased formation energy barrier (∆G) from ·O2– to the intermediate 1,4‐endoperoxide (·OOH). This work suggests that simultaneous formation of electron donating group and charge transfer channel via organic molecule bifunctionalization is a feasible strategy for boosting the photocatalytic activity of CN.

Hexagonal Hollow Porous Organic Framework Nanotubes for Efficient Photocatalytic H2O2 Production in Pure H2O under O2 Atmosphere

“…Based on the main electronic transitions (S0 → S1; highest occupied molecular orbital (HOMO) → lowest The possible mechanism of photocatalytic H 2 O 2 generation of BPYTEA-POF has been presented based on the experimental analysis and theoretical calculations. 54,55 The CB level of BPYTEA-POF is calculated to be −0.50 V vs NHE, and the VB level is calculated to be 1.52 V vs NHE (Figure S18), indicating that not only the reduction of O 2 level but also the oxidation of H 2 O is feasible in thermodynamics. As can be seen from Figure 8 The excellent photocatalytic performance of BPYTEA-POF for H 2 O 2 formation by photocatalysis is primarily ascribed to the following beneficial structure and morphological characteristics: (1) BPYTEA-POF with a hexagonal hollow nanotube structure can be easily synthesized in the absence of a template,…”

“…The possible mechanism of photocatalytic H 2 O 2 generation of BPYTEA-POF has been presented based on the experimental analysis and theoretical calculations. , The CB level of BPYTEA-POF is calculated to be −0.50 V vs NHE, and the VB level is calculated to be 1.52 V vs NHE (Figure S18), indicating that not only the reduction of O 2 level but also the oxidation of H 2 O is feasible in thermodynamics. As can be seen from Figure , when BPYTEA-POF was added to pure water, the H 2 O molecules were adsorbed and activated by BPYTEA-POF by forming a hydrogen bond between the nitrogen atom in 2,2′-bipyridine and the H 2 O molecule.…”

Improving Charge Carrier Separation through S-Scheme-Based 2D–2D WS2/Sulfur-Doped g-C3N4 Heterojunctions for a Superior Photocatalytic O2 Reduction Reaction

“…It is one of the cleanest, green, and eco-friendly oxidants with strong oxidation and reduction characteristics, possesses high oxygen content, and releases H 2 O as the only byproduct. Further, H 2 O 2 is considered an asset to the global economy in numerous directions including medical sterilization, paper and food industries, wastewater decontamination, energy, ecological protection, and chemical synthesis. − Moreover, H 2 O 2 behaves as a clean energy transporter to substitute H 2 in fuel cells because of its high energy density, solubility nature, easy storage, and safe conveyance . Currently, the industrial manufacturing of H 2 O 2 primarily depends on the conventional anthraquinone oxidation process, which meets more than 95% of the world’s H 2 O 2 consumption. , This traditional method is an energy-intensive process and expensive and inevitably discharges huge quantities of harmful byproducts into the open atmosphere .…”