Protic Salts of High Nitrogen Content as Versatile Precursors for Graphitic Carbon Nitride: Anion Effect on the Structure, Properties, and Photocatalytic Activity

Captopril supported on magnetic graphene nitride, a sustainable and green catalyst for one-pot multicomponent synthesis of 2-amino-4H-chromene and 1,2,3,6-tetrahydropyrimidine

Captopril (CAP) is a safe, cost-effective, and environmentally organic compound that can be used as an effective organo-catalyst. Functional groups of captopril make it capable to attach to solid support and acting as promoters in organic transformations. In this work, captopril was attached to the surface of magnetic graphene nitride by employing a linker agent. The synthesized composite efficiently catalyzed two multicomponent reactions including the synthesis of 1,2,3,6-tetrahydropyrimidine and 2-amino-4H-chromene derivatives. A large library of functional targeted products was synthesized in mild reaction conditions. More importantly, this catalyst was stable and magnetically recycled and reused for at least five runs without losing catalytic activity.

Versatile Synthesis of Carbon Materials using Protic Ionic Liquids and Salts as Precursors

Carbon materials (CMs) hold immense potential for applications across a wide range of fields. However, current precursors often confront limitations such as low heteroatom content, poor solubility, or complicated preparation and post-treatment procedures. Our research has unveiled that protic ionic liquids and salts (PILs/PSs), generated from the neutralization of organic bases with protonic acids, can function as economical and versatile small-molecule carbon precursors. The resultant CMs display attractive features, including elevated carbon yield, heightened nitrogen content, improved graphitic structure, robust thermal stability against oxidation, and superior conductivity, even surpassing that of graphite. These properties can be elaborate modulated by varying the molecular structure of PILs/PSs. In this Personal Account, we summarize recent developments in PILs/PSs-derived CMs, with a particular focus on the correlations between precursor structure and the physicochemical properties of CMs. We aim to impart insights into the foreseeable controlled synthesis of advanced CMs.

C-O band structure modified broad spectral response carbon nitride with enhanced electron density in photocatalytic peroxymonosulfate activation for bisphenol pollutants removal

Here, a simple one-step calcination method uses glycolic acid (GA) and urea to synthesize C-O band structure modified carbon nitride with broad spectral response, which is used to construct a peroxymonosulfate/visible light (PMS/vis) system. The solid-state ¹³C NMR proved that C-O band structure was successfully introduced into the carbon nitride. Density functional theory (DFT) calculation show that the introduction of C-O band structure shortens the band gap of 0.05 g GA modified CN (0.05 GA-CN). Besides, Ultraviolet photoelectron spectroscopy (UPS) further illustrate that the 0.05 GA-CN has a higher charge density and promotes the degradation of pollutants. In PMS/vis system, 0.05 GA-CN can completely degrade bisphenol A (BPA) within 36 min. In addition, 0.05 GA-CN can also degrade bisphenol E (BPE) and bisphenol F (BPF). The cyclic voltammetry (CV) curve show that the introduction of C-O band structure enhances the activation ability of PMS. At the same time, 0.05 GA-CN/PMS has enhanced the activity of degrading BPA under blue light (450-462 nm), green light (510-520 nm) and red light (610-625 nm). This research provides a new method to synthesize carbon nitride with enhanced electron density for degradation of bisphenol pollutants in PMS/vis system.

Graphitic Carbon Nitride Nanosheets Covalently Functionalized with Biocompatible Vitamin B1: Synthesis, Characterization, and Its Superior Performance for Synthesis of Quinoxalines

The physical properties of two-dimensional nanosheet materials make them promising candidates as active materials in the areas of photoelectronics, fuel cells, sensors, water splitting, solar energy conversion, CO2 reduction, and heterogeneous catalysis. Among two-dimensional nanosheet materials, graphitic carbon nitride due to its electronic structure and high chemical and thermal stability possesses unique properties. Covalent functionalization of graphitic carbon nitride could be the key step in modifying its ability and significantly improving its properties. To this purpose, a novel strategy for the covalent functionalization of g-C3N4 nanosheets (CN) with vitamin B1 (VB1) by using 1,3-dibromopropane as a covalent linker for the first time is demonstrated. The obtained CN-Pr-VB1 exhibits increased thermal stability compared to the VB1 which is important in the practice application and can be easily dispersed in common organic solvents. The efficacy of the CN-Pr-VB1 as a heterogeneous organocatalyst was evaluated in the quinoxaline synthesis under solvent-free conditions and afforded good isolated yield with high purity. Moreover, the prepared catalyst could be facilely recycled and reused for seven consecutive cycles without a noticeable decrease in the catalytic activity. Extensive characterization confirmed the stability of morphology and chemical structure after recyclability of the CN-Pr-VB1.

One-pot construction of Cu and O co-doped porous g-C3N4 with enhanced photocatalytic performance towards the degradation of levofloxacin

Cu and O co-doped porous g-C₃N₄ with outstanding photocatalytic degradation of levofloxacin performance was synthesized by a one-pot thermal polymerization approach.

Facile synthesis of carbon quantum dots loaded with mesoporous g-C3N4 for synergistic absorption and visible light photodegradation of fluoroquinolone antibiotics

mpg-C₃N₄/CQDs was prepared by using a facile synthetic approach and applied for the synergistic absorption and photocatalytic degradation of FQs.

Structural characterization and electrochemical performance of macroporous graphite-like C3N3 prepared by the Wurtz reaction and heat treatment

g-C₃N₃ is synthesized by a facile method and further heat treatment can improve the initial coulombic efficiency and reversible capacity.

An autonomous actuator driven by fluctuations in ambient humidity

Devices that respond to negligibly small fluctuations in environmental conditions will be of great value for the realization of more sustainable, low-power-consumption actuators and electronic systems. Herein we report an unprecedented film actuator that seemingly operates autonomously, because it responds to the adsorption and desorption of a minute amount of water (several hundred nanograms per 10 mm(2)) possibly induced by fluctuations in the ambient humidity. The actuation is extremely rapid (50 ms for one curl) and can be repeated >10,000 times without deterioration. On heating or light irradiation, the film loses adsorbed water and bends quickly, so that it can jump vertically up to 10 mm from a surface or hit a glass bead. The film consists of a π-stacked carbon nitride polymer, formed by one-pot vapour-deposition polymerization of guanidinium carbonate, and is characterized by a tough, ultralightweight and highly anisotropic layered structure. An actuator partially protected against water adsorption is also shown to walk unidirectionally.