Photochemical Construction of Carbonitride Structures for Red‐Light Redox Catalysis

Abstract

Metal-free carbonitride(CN) semiconductors are appealing light-transducers for photocatalytic redox reactions owing to the unique band gap and stability. To harness solar energy efficiently, CN catalysts that are active over a wider range of the visible spectrum are desired. Now a photochemical approach has been used to prepare a new-type triazine-based CN structure. The obtained CN shows extraordinary light-harvesting characteristics, with suitable semiconductor-redox potentials. The light absorption edge of the CN reaches up to 735 nm, which is significantly longer than that of the conventional CN semiconductor at about 460 nm. As expected, the CN can efficiently catalyze oxidation of alcohols and reduction of CO with visible light, even under red-light irradiation. The results represent an important step toward the development of red-light-responsive triazine-based structures for solar applications.

Nanostructured Carbon Nitrides for CO2 Capture and Conversion

“…Same group previously prepared mesoporous carbon nitride, C 3 N 4 , from melamine and 12 nm silica nanoparticles via hard templating method and carried out the photocatalytic CO 2 reduction under exactly the same conditions, which yielded 6.3 mol h −1 of CO and 0.6 mol h −1 of H 2 gas with turn over number of 6.9 and 91.3% selectivity . Yang et al prepared a new triazine‐based CN having a quasi‐2D lamellar like polymer structure and extended light absorption edge up to 735 nm through the simple polymerization between melamine and cyanuric chloride via photochemical approach by using UV light under ambient conditions . As‐prepared CN material exhibited an admirable amount of CO 2 uptake capacity compared with the polymeric carbon nitride (PCN) due to the presence of abundant NH x /OH groups as Lewis bases and showed high photocatalytic CO 2 reduction activity for the generation of CO (1.8 mmol) upon 420 nm light‐emitting diode (LED) irradiation for 1 h duration.…”

Intramolecular Charge Transfer and Extended Conjugate Effects in Donor–π–Acceptor‐Type Mesoporous Carbon Nitride for Photocatalytic Hydrogen Evolution

“…The unfettered migration resultsi nf ast charger ecombination and al oss of efficient electrons in the conduction band (CB), which is considered the main reasonf or the unsatisfactory photocatalytic efficiency of carbon nitride materials. [9][10][11] To enhancet he performance of g-C 3 N 4 ,v ariouss trategies have been implemented, including element doping, [12][13][14][15] morphology design, [16][17][18][19][20][21][22][23][24][25] molecule coupling, [26][27][28][29][30][31] and reactions ystem optimization. [32,33] Even so, thesec onventional strategiess till suffer from limited carriers eparation.…”

Electrochemiluminescence for Characterizing the Polymerization Process during Graphitic Carbon Nitride Synthesis

“…Owing to its unique physicochemical properties, g‐CN has attracted extensive attention in the fields including solar energy conversion, water splitting, electrochemical devices, chemo‐/bio‐sensing, bioimaging, and cancer therapy . g‐CN is usually synthesized by either bulk condensation at high temperature 3 or solvothermal condensation at low temperature . g‐CN with different degree of polymerization can be obtained by tuning condensation conditions like temperature and reaction time .…”

“…g‐CN is usually synthesized by either bulk condensation at high temperature 3 or solvothermal condensation at low temperature . g‐CN with different degree of polymerization can be obtained by tuning condensation conditions like temperature and reaction time . As a polymer semiconductor, polymerization degree of g‐CN greatly affects its physicochemical properties and application performances .…”