Facile preparation and high photocatalytic activity of crystalline graphitic carbon nitride in hydrogen evolution from electron donor solutions under visible light

Dependency of Crystal Violet Dye Removal Behaviors onto Mesoporous V2O5-g-C3N4 Constructed by Simplistic Ultrasonic Method

This research examined the production of a V2O5-g-C3N4 nanocomposite to remove organic dyes from wastewater. To generate the V2O5-g-C3N4 nanocomposite, the sonication method was applied. The testing of V2O5-g-C3N4 with various dyes (basic fuchsin (BF), malachite green (MG), crystal violet (CV), Congo red (CR), and methyl orange (MO)) revealed that the nanocomposite has a high adsorption ability towards BF, MG, CV, and CR dyes in comparison with MO dye. It was established that the modification of pH influenced the removal of CV by the V2O5-g-C3N4 nanocomposite and that under optimal operating conditions, efficiency of 664.65 mg g−1 could be attained. The best models for CV adsorption onto the V2O5-g-C3N4 nanocomposite were found to be those based on pseudo-second-order adsorption kinetics and the Langmuir isotherm. According to the FTIR analysis results, the CV adsorption mechanism was connected to π–π interactions and the hydrogen bond.

Ion-Induced Synthesis of Crystalline Carbon Nitride Ultrathin Nanosheets from Mesoporous Melon for Efficient Photocatalytic Hydrogen Evolution with Synchronous Highly Selective Oxidation of Benzyl Alcohol

Crystalline carbon nitride (CCN) with a poly(heptazine imide) structure is efficient in photocatalytic hydrogen evolution (PHE), but synthesis of CCN ultrathin nanosheets (CCNuns) and their use in PHE with selective organic oxidation are still rare. Herein, CCNuns with Na⁺ doping are prepared using NaCl as the ion-induction and templating agent and mesoporous melon as the feedstock, exhibiting efficient synchronous PHE and benzyl alcohol oxidation to benzaldehyde, with an apparent quantum yield of 10.5% at 420 nm and a visible light PHE rate that is 94.3 times that of bulk polymeric carbon nitride (PCN). The selectivity of benzaldehyde formation (90.5%) is also much higher than that of PCN (40.7%). Interestingly, this selectivity increases gradually with increasing light wavelengths. The high photoactivity of CCNuns originates from their ultrathinness and Na⁺ doping, which considerably enhance the photogenerated charge separation. This work opens up an avenue for the synthesis of CCNuns and extends their application.