Graphitic carbon nitride nanomaterials integrating optical absorption and membrane performance for solar distillation
- 1Physics Department, Faculty of Education, Ain Shams University Roxy Cairo 11757 Egypt [email protected].
- 2Egypt Desalination Research Center of Excellence (EDRC), Hydrogeochemistry Dept., Desert Research Center Cairo 11753 Egypt.
Abstract
Graphitic carbon nitride (g-C₃N₄) nanomaterials offer high potential for solar-driven membrane distillation (MD), yet balancing optical absorption with mass transport stability remains challenging. Herein, nanocrystalline g-C₃N₄ thin films were fabricated via spray pyrolysis and integrated into polyvinyl alcohol (PVA)-coated polytetrafluoroethylene (PTFE) membranes to form photothermally active antiwetting barriers. Microstructural analysis revealed a polycrystalline structure with an average crystallite size of 36.6 nm and a compressive microstrain (ε = 0.0047), which promotes non-radiative energy dissipation for photothermal heating. Spectroscopic modeling using the Wemple-DiDomenico single-oscillator approach yielded an oscillator energy (E o) of 5.65 eV, dispersion energy (E d) of 16.5 eV, and a high-frequency dielectric constant (ε ∞) of 4.28. Crucially, embedding g-C₃N₄ into the PVA matrix narrowed the optical bandgap from 2.49 eV to 2.13 eV, shifting the absorption edge toward 582 nm and enabling enhanced solar spectrum utilization. Under photothermal testing, the PVA/g-C₃N₄ coating achieved a localized surface temperature of 62.7 °C under low irradiation. In MD tests, although the PVA/g-C₃N₄ coating introduced transport resistance (reducing the permeability coefficient from 0.58 to 0.23 L m⁻² h⁻¹ °C⁻¹), it dramatically enhanced long-term durability. While pristine PTFE suffered catastrophic pore wetting and complete flux loss within 10 h, the PVA/g-C₃N₄ membrane maintained stable operation for 20 h (1200 min) with ∼54% flux retention and excellent salt rejection (>99.5%). This study establishes a structure-property relationship demonstrating that sacrificing initial permeability for photothermal stability and antiwetting resistance is essential for practical solar desalination.
Related
- Unveiling the Influence of Graphitic Nanocarbon Structures, Defects, and Surface Functional Groups on Supercapacitive Performance in LiTFSI Electrolyte
- Novel carbonyl iron-mediated synthesis of Pd–Fe magnetic nanomaterials: mechanism and catalytic performance in Suzuki coupling
- Photocatalytic Performance of TiO2-Based Nanomaterials for Water Remediation
- Nanomaterials Assessment Tool (NAT): A novel open-access framework for performance and sustainability evaluation
- Tribological Performance of FFF-Printed PLA and PLA-Wood Parts: The Effects of Infill Architecture, Heat Treatment, and Water Absorption
BibTeX
@article{ebraheem2026graphitic,
title = {{Graphitic carbon nitride nanomaterials integrating optical absorption and membrane performance for solar distillation}},
author = {Bassant Ebraheem and H I Lebda and M M El-Nahass and A A M Farag and H A Shawky and Mohamed E A Ali},
journal = {RSC advances},
year = {2026},
month = nov,
doi = {10.1039/d6ra04938a},
url = {https://europepmc.org/article/PMC/PMC13726137},
note = {CC BY-NC},
}
RIS
TY - JOUR
TI - Graphitic carbon nitride nanomaterials integrating optical absorption and membrane performance for solar distillation
AU - Bassant Ebraheem
AU - H I Lebda
AU - M M El-Nahass
AU - A A M Farag
AU - H A Shawky
AU - Mohamed E A Ali
PY - 2026
DA - 2026/11/02
JO - RSC advances
DO - 10.1039/d6ra04938a
UR - https://europepmc.org/article/PMC/PMC13726137
AB - Graphitic carbon nitride (g-C₃N₄) nanomaterials offer high potential for solar-driven membrane distillation (MD), yet balancing optical absorption with mass transport stability remains challenging. Herein, nanocrystalline g-C₃N₄ thin films were fabricated via spray pyrolysis and integrated into polyvinyl alcohol (PVA)-coated polytetrafluoroethylene (PTFE) membranes to form photothermally active antiwetting barriers. Microstructural analysis revealed a polycrystalline structure with an average crystallite size of 36.6 nm and a compressive microstrain (ε = 0.0047), which promotes non-radiative energy dissipation for photothermal heating. Spectroscopic modeling using the Wemple-DiDomenico single-oscillator approach yielded an oscillator energy (E o) of 5.65 eV, dispersion energy (E d) of 16.5 eV, and a high-frequency dielectric constant (ε ∞) of 4.28. Crucially, embedding g-C₃N₄ into the PVA matrix narrowed the optical bandgap from 2.49 eV to 2.13 eV, shifting the absorption edge toward 582 nm and enabling enhanced solar spectrum utilization. Under photothermal testing, the PVA/g-C₃N₄ coating achieved a localized surface temperature of 62.7 °C under low irradiation. In MD tests, although the PVA/g-C₃N₄ coating introduced transport resistance (reducing the permeability coefficient from 0.58 to 0.23 L m⁻² h⁻¹ °C⁻¹), it dramatically enhanced long-term durability. While pristine PTFE suffered catastrophic pore wetting and complete flux loss within 10 h, the PVA/g-C₃N₄ membrane maintained stable operation for 20 h (1200 min) with ∼54% flux retention and excellent salt rejection (>99.5%). This study establishes a structure-property relationship demonstrating that sacrificing initial permeability for photothermal stability and antiwetting resistance is essential for practical solar desalination.
SN - 2046-2069
ER -