ReviewTwo-dimensional graphitic carbon nitride-based membranes for filtration process: Progresses and challenges
Introduction
In the context of resource management and sustainable development, the efficient, rapid and inexpensive separation of the various molecules and/or pollutants from aqueous, organic solutions and gas mixtures is essential.[1] Therefore, energy efficient and environmentally friendly separation methods are required to significantly reduce the cost of processing liquid and gaseous mixtures for purification, recovery and recycling. Membrane separation technologies are recognized as efficient and economically profitable separation techniques, they present a simple operating process with a high separation rate, they have a wide range of applications in the industrial environment such as the water purification by desalination of sea water.[2], [3], [4], [5], [6] Compared to traditional separation methods for water treatment, pressure-driven membrane separation processes offer multiple benefits, including energy efficiency, easy integration and scalability. Membrane filtration has particularly attracted a lot of attention due to its unique advantages in the purification of wastewater and the separation of organic molecules, multivalent ions and industrial residues. Depending on the size of the pores, the purification process can be classified as microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), reverse osmosis (RO) and forward osmosis (FO). [5], [7], [8], [9], [10], [11] The filtration processes was commonly based on polymeric membranes such as Polyvinyl Alcohol (PVA), Polyether sulfone (PES), Polyvinylidene fluoride (PVDF), Polyvinyl chloride (PVC), Polypropylene (PP), Polyacrylonitrile (PAN), Polyimide (PI), Polyethylene (PE), Polyvinyl Alcohol (PVA) Cellulose Acetate (CA), etc. However, polymeric membranes have usually exhibited a tradeoff between permeability and selectivity and had a problem of fouling. Since the use of conventional polymer membranes for water treatment has had certain limitations, these limitations have led researchers to introduce nanotechnology with nanoporous membranes to increase the performance of the membrane separation. [11], [12] Among nanoporous membranes, 2D nanomaterials-based membranes have demonstrated exceptional properties in the field of membrane separation.[13], [14], [15], [16], [17] Graphene and its derivatives paved the way in the using of 2D nanomaterials-based membrane for separation. [18], [19], [20], [21], [22], [23], [24] Other 2D structures, such as MXenes, among others, have been object of recent investigations in the field of membrane separation. [25], [26], [27], [28], [29], [30] Similar to graphite, graphitic carbon nitride (g-C3N4) a sp2 hybridized material, have aroused much interest in recent years owing to is layered structure involving weak Van der Waals interactions between adjacent C-N layers. [31] g-C3N4 is a semiconductor photocatalyst with visible-light response. The band gap energy of g-C3N4 is 2.7 eV and its maximum adsorption wavelength is around 460 nm. The g-C3N4 also possesses many advantages, such as strong mechanical property, large surface area, non-toxic nature, and facile synthesis readily available precursor. [15], [31], [32], [33] Taking these advantages into account, g-C3N4 has been a revolutionary material in the construction of membranes with high separation performance and having photocatalytic properties allowing the decrease of membrane fouling. Since its synthesis in the 19th century by the work carried out by Berzelius and Liebig as well as the discovery reported by Wang et al. in 2009 as a metal-free conjugated semiconductor photocatalyst for hydrogen, various nanostructures of g-C3N4 were developed, namely 0D quantum dots, 1D nanotubes-nanofibers-nanowires-nanorods, 2D nanosheets and 3D microspheres. This has given researchers a wide range of choice of g-C3N4 based nanomaterials for the design and construction of composite membranes with superior separation performances. [32], [34], [35] The possibility of modulating the physico-chemical properties of g-C3N4 allows the adjustment of the functionalities of membranes based on the latter. Thus, g-C3N4 has become one of the main materials in membrane separation. More than two hundred articles on g-C3N4-based membranes have already been published to date, and it is from the year 2016 that the research aroused particular interest on the part of researchers because the publications have been multiplied due to the great fascination offered by this material. Fig. 1 traces the publications relating to g-C3N4-based membranes from 2011 to 2020. For the last 5 years, our research group has focused on 2D membranes [118], [121], [141] as well as 2D photocalytic membranes [139], [140], [142] for water filtration. On the basis of our own experiments, we therefore set out to study the filtration performance of 2D g-C3N4 membranes by clarifying the synthesis of the nanosheets as well as the preparation of membranes and the application in filtration processes. Thus, this review summarizes the trends on 2D g-C3N4 synthesis as well as that on g-C3N4-based photocatalytic membranes while highlighting the influence of membrane microstructure on separation performance and attempts to provide future directions in which the field is likely to come true.
Section snippets
Synthesis and properties of g-C3N4
Before talking about 2D g-C3N4-based membranes, the intrinsic synthesis and properties of g-C3N4-based materials will be briefly presented, as they strongly determine the quality of the membrane, the microstructures and the separation performance.
Progress on 2D g-C3N4-based membrane
The recent development of the 2D-enabled membrane architecture shows a distinctive pattern that differs from the development of the conventional polymeric membrane designs.[16] The rapid growth in interest and the large number of studies in recent years suggests that 2D g-C3N4-based membranes are becoming a family of high separation performance membranes. The low nanometric thickness, the high specific surface area as well as the high hydrophily of the nanosheets have stimulated the continuous
Challenges in 2D g-C3N4-based membranes for filtration
Though significant progresses have been achieved, several challenges are still to be faced, and some of the issues must be solved before g-C3N4-based photocatalytic membranes can be used in practical applications. Based on the studies investigated, we propose the following:
- (1)
Since polymeric substrates such as CA, PVDF, PTFE, etc and ceramic substrates are different in term of their structures and surface properties, their interaction with g-C3N4 to form lamellar membranes, mixed matrix membranes,
Conclusions and perspectives
The development of the transport and communication industry, the proliferation of chemical fertilizer factories, etc. have resulted in increased water pollution. Until then, filtration was an alternative to water pollutants, but the development of industries has made commercial polymeric membranes obsolete. However, membrane filtration is remaining the effective method for water treatment. Membranes based on 2D nanomaterials have made it possible to revitalize the field of membrane filtration
Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgements
This work was financially supported by the Hunan Provincial Science and Technology Plan Project, China (No. 2016TP1007) and Hunan Provincial Natural Science Foundation of China (No. 2020JJ4107). Kai Han acknowledges the support from Innovation-Driven Project of Central South University (No. 2020CX037).
References (141)
- et al.
Recent Advances in Nanoporous Membranes for Water Purification
Nanomaterials
(2018) - et al.
Ultrathin two-dimensional MXene membrane for pervaporation desalination
J. Membr. Sci.
(2018) - et al.
Fabrication of g-C3N4/Ti3C2TX Composite and Its Visible-Light Photocatalytic Capability for Ciprofloxacin Degradation
Sep. Purif. Technol.
(2019) - et al.
The Effect of Graphitic Carbon Nitride Precursors on the Photocatalytic Dye Degradation of Water-Dispersible Graphitic Carbon Nitride Photocatalysts
Appl. Surf. Sci.
(2021) - et al.
Water Permeability and Water/Salt Selectivity Tradeoff in Polymers for Desalination
J. Membr. Sci.
(2011) - et al.
Evaluation of Self-Cleaning and Photocatalytic Properties of Modified g-C3N4 Based PVDF Membranes Driven by Visible Light
J Colloid Interface Sci
(2019) - et al.
Water Desalination across Multilayer Graphitic Carbon Nitride Membrane: Insights from Non-Equilibrium Molecular Dynamics Simulations
Carbon
(2018) - et al.
Photocatalytic Self-Cleaning Carbon Nitride Nanotube Intercalated Reduced Graphene Oxide Membranes for Enhanced Water Purification
Chem. Eng. J.
(2019) - et al.
Photocatalytic Properties of PVDF Membranes Modified with g-C3N4 in the Process of Rhodamines Decomposition
Sep. Purif. Technol.
(2020) - et al.
Graphene Oxide Modified Graphitic Carbon Nitride as a Modifier for Thin Film Composite Forward Osmosis Membrane
J. Membr. Sci.
(2015)
A Mussel-Inspired Method to Fabricate Reduced Graphene Oxide/g-C3N4 Composites Membranes for Catalytic Decomposition and Oil-in-Water Emulsion Separation
Chem. Eng. J.
Integration of Membrane Filtration and Photoelectrocatalysis on g-C3N4/CNTs/Al2O3 Membrane with Visible-Light Response for Enhanced Water Treatment
J. Membr. Sci.
Graphitic Carbon Nitride (g-C3N4) Nanosheets Functionalized Composite Membrane with Self-Cleaning and Antibacterial Performance
J Hazard Mater
Super Hydrophilic Composite Membrane with Photocatalytic Degradation and Self-Cleaning Ability Based on LDH and g-C3N4
J. Membr. Sci.
Integration of Microfiltration and Visible-Light-Driven Photocatalysis on g-C3N4 Nanosheet/Reduced Graphene Oxide Membrane for Enhanced Water Treatment
Appl. Catal. B
Comparison of NLDH and g-C3N4 Nanoplates and Formative Ag3PO4 Nanoparticles in PES Microfiltration Membrane Fouling: Applications in MBR
Chem. Eng. Res. Des.
A Novel Antibacterial Mixed Matrixed Pes Membrane Fabricated from Embedding Aminated Ag3PO4/g-C3N4 Nanocomposite for Use in the Membrane Bioreactor
J. Ind. Eng. Chem.
Photocatalytic Properties of PVDF Membranes Modified with g-C3N4 in the Process of Rhodamines Decomposition
Sep. Purif. Technol.
H2O2-Assisted Photocatalysis for Removal of Natural Organic Matter Using Nanosheet C3N4-WO3 Composite under Visible Light and the Hybrid System with Ultrafiltration
Chem. Eng. J.
Hydrophilic Hierarchical Carbon with TiO2 Nanofiber Membrane for High Separation Efficiency of Dye and Oil-Water Emulsion
Sep. Purif. Technol.
Nano CuO/g-C3N4 Sheets-Based Ultrafiltration Membrane with Enhanced Interfacial Affinity, Antifouling and Protein Separation Performances for Water Treatment Application
J Environ Sci (China)
Nanoscale Tailor-Made Membranes for Precise and Rapid Molecular Sieve Separation
Nanoscale
Welcome to Membranes — a New Open Access Journal on Membrane Separation and Technology
Membranes
Study of the Effect of Nanoparticles and Surface Morphology on Reverse Osmosis and Nanofiltration Membrane Productivity
Membranes
Role of Nanocomposite Support Stiffness on TFC Membrane Water Permeance
Membranes
Recent Trends in Nanofibrous Membranes and Their Suitability for Air and Water Filtrations
Membranes
Membranes for Environmentally Friendly Energy Processes
Membranes
Membranes with Intrinsic Micro-Porosity: Structure, Solubility, and Applications
Membranes
Membranes with Surface-Enhanced Antifouling Properties for Water Purification
Membranes
Permeability-Selectivity Analysis of Microfiltration and Ultrafiltration Membranes: Effect of Pore Size and Shape Distribution and Membrane Stretching
Membranes
Nanocomposites for Improved Physical Durability of Porous PVDF Membranes
Membranes
Progress of Nanocomposite Membranes for Water Treatment
Membranes
2D-Enabled Membranes: Materials and Beyond, BMC
Chem. Eng.
PVDF Based Nanocomposite Membranes: Application Towards Wastewater Treatment
Madridge Journal of Nanotechnology & Nanoscience
Two-Dimensional Nanomaterials for Photocatalytic Water Disinfection: Recent Progress and Future Challenges
J. Chem. Technol. Biotechnol.
Two-Dimensional-Material Membranes: A New Family of High-Performance Separation Membranes
Angew Chem Int Ed Engl
Recent Progress in Two-Dimensional-Material Membranes for Gas Separation
Acta Phys. Chim. Sin.
Graphene-Based Membranes
Chem Soc Rev
Graphene Membranes for Water Desalination
NPG Asia Mater.
Fabrication of Reduced Graphene Oxide Membranes for Highly Efficient Water Desalination
RSC Adv.
Graphene-Based Membranes: Status and Prospects, Philos Trans A Math Phys
Eng Sci
Unimpeded Permeation of Water through Helium-Leak–Tight Graphene-Based Membranes
Science
Ultrafast Viscous Water Flow through Nanostrand-Channelled Graphene Oxide Membranes
Nat Commun
Ultrathin graphene-based membrane with precise molecular sieving and ultrafast solvent permeation
Nat. Mater.
Two-Dimensional Lamellar Membrane: Mxene Nanosheet Stacks
Angew Chem Int Ed Engl
Charge- and Size-Selective Ion Sieving through Ti3C2Tx Mxene Membranes
J. Phys. Chem. Lett.
Preparation of a New 2D Mxene/PES Composite Membrane with Excellent Hydrophilicity and High Flux
RSC Adv.
Ultrahigh-Flux and Fouling-Resistant Membranes Based on Layered Silver/Mxene (Ti3C2Tx) Nanosheets
J. Mater. Chem. A
Two-Dimensional Ti2CTxmxene Membranes with Integrated and Ordered Nanochannels for Efficient Solvent Dehydration
J. Mater. Chem. A
Visible light response ZnO-C3N4 thin film photocatalyst
Rare Met.
Cited by (42)
High-performance robust graphitic carbon nitride nanosheets embedded membranes for desalination through direct contact membrane distillation
2024, Journal of Industrial and Engineering ChemistryHeterogeneous MIL-88A on MIL-88B hybrid: A promising eco-friendly hybrid from green synthesis to dual application (Adsorption and photocatalysis) in tetracycline and dyes removal
2024, Journal of Colloid and Interface ScienceFunctionalized graphite carbon nitride nanofluid membranes for enhanced osmotic energy harvesting
2024, Journal of Electroanalytical Chemistry