Na-Doped Graphitic Carbon Nitride for Removal of Aqueous Contaminants via Adsorption and Photodegradation

Abstract

Graphitic carbon nitride (g-CN) has gained significant popularity as a visible-light-activated photocatalyst in energy and environmental applications. Most papers are dedicated to improving its photocatalytic performance; however, an investigation of its adsorption performance not only expands its application scope but also provides insight into its surface interactions. Herein, sodium-doped g-CN (Na(x)-CN) is synthesized via one-step pyrolysis of the mixture of melamine and sodium carbonate (Na2CO3). The prepared Na(x)-CN not only demonstrates superior adsorption capacities (maximum adsorption capacity of methylene blue up to 1319 mg/g, which is ∼650 times higher than that of the pristine g-CN) but also overcomes the lack of selectivity and slow adsorption kinetics of commonly used adsorbents. The extraordinary adsorption capacities are mainly attributed to π–π interactions and electrostatic interactions. Moreover, the Na2CO3-assisted synthesis route improved the optical properties and photocarrier separation efficiency, which are beneficial for further removal of contaminants via photodegradation. This work introduces a facile route for mass production of Na-doped g-CN with excellent adsorption capacities and selectivity as well as enhanced photocatalytic performance.

Visible Light-Driven Highly Selective CO2 Reduction to CH4 Using Potassium-Doped g-C3N5

“…We see that the doping of K does not alter the out-of-plane bending mode at ∼810 cm −1 , which is observed in all aromatic CN compounds. 40,41 The vibrational bands in the range of 890−1690 cm −1 are indicative of the stretching modes of the CN heterocycles that are consistent even with doping. 42 The influence of K doping is clearly reflected in the band positioned at 2141 cm −1 for g-C 3 N 5 and its observed shift toward a higher frequency (2181 cm −1 ) with K doping.…”

In Situ Remediation Technology for Heavy Metal Contaminated Sediment: A Review

“…MXenes is a two-dimensional transition metal carbide or nitride material with advantages of excellent conductivity, high specific surface area, rich surface functionalities, mechanical flexibility and hydrophilicity, and their adsorption capacity for heavy metals depends upon their surface terminal groups (-OH, -F, and -O) and interlayer spacing [ 105 ]. Graphitic carbon nitride (g-C 3 N 4 ) is a two-dimensional metal-free semiconductor that has multiple surface features and abundant functional groups (e.g., -NH 2 /-NH-/=NA-), making it a promising adsorbent for pollutant elimination [ 80 , 106 ]. Although nanomaterials have great potential to remedy heavy metal contamination, they are rarely used in commercial applications.…”

Plasmon Au/K-doped defective graphitic carbon nitride for enhanced hydrogen production

“…Alkali metals (K, Na, Zn) have been used to date to modify g-C 3 N 4 . 23,24 Potassium, as an alkali metal, is commonly doped in the g-C 3 N 4 framework. Su et al prepared K-doped g-C 3 N 4 by a solid-template induced growth method.…”