A Novel BiOCl Based Nanocomposite Membrane for Water Desalination

Abstract

In this study, BiOCl based nanocomposites were used as photocatalytic membranes for a simulated study on water desalination in reverse osmosis membrane systems. Through molecular dynamic simulation, the molecular structure of BiOCl, BiOCl/Ag2S and BiOCl/Bi2O3 heterojunctions were designed and their electronic properties, mechanical properties, and membrane performance for water desalination were evaluated for the first time. The molecular structure was created, and a geometry optimization task was used to optimize it. Material Studio 2019 CASTEP was used for simulation of the electronic and mechanical properties and water desalination was performed by ReaxFF software under pressures between 0 and 250 MPa. The novel BiOCl based nanocomposites showed improved electronic and mechanical properties and, most importantly, improvements in salt rejection and water permeability as compared to well-known materials such as graphene and MoS2. BiOCl and BiOCl/Ag2S had a bandgap around two, which is the ideal bandgap for semiconductor photocatalysts. A salt rejection of 98% was achieved under an applied pressure of 10 MPa. Salt rejection was higher for BiOCl/Bi2O3, while water permeability was higher for BiOCl/Ag2S. The monolayer BiOCl was unstable under pressures higher than 50 MPa, but the mechanical stability of BiOCl/Ag2S increased twofold and increased fourfold for BiOCl/Bi2O3, which is even higher than MoS2. However, between the three nanocomposites, BiOCl/Ag2S was found to be the most ideal photocatalytic nanocomposite membrane.

Surface/interfacial transport through pores control desalination mechanisms in 2D carbon-based membranes

“…below are the average of the three duplicate simulations. Finally, the ion movement under the electric field was simulated to estimate the self-cleaning property of Carzeo-ANG using Material Studio 35 (S4, ESI †).…”

“…To eliminate the influence of random factors and improve the result accuracy of the desalination properties, three MD simulations were performed for each system, and the data reported below are the average of the three duplicate simulations. Finally, the ion movement under the electric field was simulated to estimate the self-cleaning property of Carzeo-ANG using Material Studio 35 (S4, ESI†).…”

“…In the simulation phase, we applied five different pressures (20,35,50,65, and 80 MPa) to the graphene piston and filtered the simulation fluid through the Carzeo-ANG membrane to the pure water area. [57][58][59] We discovered that the salt ions and water molecules would not pass through the non-activated Carzeo-ANG membrane without pressure.…”

Calculation of Mechanical Properties, Electronic Properties, and Thermodynamic Properties of AuAl Crystal: First‐Principles Calculation

“…[ 17 ] CASTEP code has been successfully used to calculate the physical properties of materials, such as thermodynamic properties, mechanical properties, and optical properties. [ 18,19 ] The ultrasoft pseudopotential was utilized to estimate the interactions between electrons and core ions, in which the valence electronic configurations for Au and Al atoms were 5d 10 6s 1 and 3s 2 3p 1 , respectively. [ 20 ]…”

“…[17] CASTEP code has been successfully used to calculate the physical properties of materials, such as thermodynamic properties, mechanical properties, and optical properties. [18,19] The ultrasoft pseudopotential was utilized to estimate the interactions between electrons and core ions, in which the valence electronic configurations for Au and Al atoms were 5d 10 6s 1 and 3s 2 3p 1 , respectively. [20] The generalized gradient approximation (GGA) in the form of Perdew-Burke-Ernzerhof (PBE) depends on the electron density and its gradient at each space point and is used to calculate the exchange-related energy.…”