Preparation and Pb (II) adsorption in aqueous of 2D/2D g‐C₃N₄/MnO₂ composite

Abstract

A novel g‐C3N4/MnO2 composite was prepared by in situ deposition of MnO2 on graphitic carbon nitride (g‐C3N4) nanosheets, and its adsorption properties were evaluated for removal of Pb (II) in aqueous. Fourier transform‐infrared, spectrometer scanning electron microscopy and transmission electron microscopy characterization showed the g‐C3N4/MnO2 composite had a two‐dimensional/two‐dimensional (2D/2D) structure with ample active sites. The Brunauer–Emmett–Teller specific surface area of g‐C3N4/MnO2 composites (234.9 m2/g) was 13.5 times larger than that of g‐C3N4 (17.37 m2/g), providing better conditions for adsorption. The adsorption kinetic data were better fitted with the pseudo‐second‐order model. The Langmuir model was more suitable for describing the experimental equilibrium data of g‐C3N4/MnO2, and the maximum adsorption capacity was 204.1 mg/g for Pb (II). The adsorption of g‐C3N4/MnO2 composite for Pb (II) was an endothermic and spontaneous process, and reached adsorption equilibrium rapidly within initial 150 min. This composite was an excellent adsorbent because of its higher adsorption capacity and facile preparation progress.

Evaluation of polymeric g-C3N4 contained nonhierarchical ZnV2O6 composite for energy-efficient LED assisted photocatalytic mineralization of organic pollutant

“…The obtained spectrum for pure g-C 3 N 4 highlights the peak in the 3500-3750 cm −1 range which is because of stretching vibrations of -NH 2 , -NH, and adsorbed water molecules. Also, a peak within 500-750 cm −1 accounts for the vibrations of triazine units that confirms the formation of g-C 3 N 4 [31]. Further, the ZnV 2 O 6 has its characteristic peaks at around 774 cm −1 indicating the asymmetric vibrations of V-O-Zn and V-O-V [19].…”

Enhancement of Pb(ii) adsorptive removal by incorporation of UiO-66-COOH into the magnetic graphitic carbon nitride nanosheets

“…9d presents the Weber–Morris intraparticle diffusion model plot which could not be fitted by a single straight line but could be divided into two linear sections suggesting that there are other rate-limiting steps besides intraparticle diffusion. 40 The first step (the initial 20 minutes) suggests a rapid diffusion of Pb( ii ) particles from the solution to the external surface of g-C 3 N 4 /Fe 3 O 4 /UiO-66-COOH or boundary layer. The process of intraparticle diffusion, which occurs during the second stage of adsorption, is responsible for the migration of Pb( ii ) from the exterior surface to the internal pores of g-C 3 N 4 /Fe 3 O 4 /UiO-66-COOH.…”

Phosphorylated cellulose/electrospun chitosan nanofibers media for removal of heavy metals from aqueous solutions

“…Lakhdhar et al 53 used CS/PEO nanofibers to adsorb Cu (II) and obtained an experimental adsorption capacity of approximately 100 mg/g, which is not far from the result of this study (74.53 mg/g). A novel g‐C 3 N 4 /MnO 2 composite was prepared by Guo et al 54 by in situ deposition of MnO 2 on graphitic carbon nitride (g‐C 3 N 4 ) nanosheets and Fan et al 55 prepared an alkali‐treated persimmon fallen leaves for removal of Pb (II) in aqueous solutions. Arshadi et al 56 , Kataria et al, 57 and Melo et al 58 used barley straw ash, ZnO nanoflowers, and tururi fibers, respectively, for adsorption of Cd (II) aqueous solutions.…”