Graphene, the thinnest, strongest, and stiffest material with exceptional thermal conductivity and electron mobility, has increasingly received world‐wide attention in the past few years. These unique properties may lead to novel or improved technologies to address the pressing global challenges in many applications including transparent conducting electrodes, field effect transistors, flexible touch screen, single‐molecule gas detection, desalination, DNA sequencing, osmotic energy production, etc. To realize these applications, it is necessary to transfer graphene films from growth substrate to target substrate with large‐area, clean, and low defect surface, which are crucial to the performances of large‐area graphene devices. This critical review assesses the recent development in transferring large‐area graphene grown on Fe, Ru, Co, Ir, Ni, Pt, Au, Cu, and some nonmetal substrates by using various synthesized methods. Among them, the transfers of the most attention kinds of graphene synthesized on Cu and SiC substrates are discussed emphatically. The advances and the main challenges of each wet and dry transfer method for obtaining the transferred graphene film with large‐area, clean, and low defect surface are also reviewed. Finally, the article concludes the most promising methods and the further prospects of graphene transfer.

Biofouling, as one of the membrane foulings, is the major obstacle limiting the application of polyamide (PA) thin-film composite (TFC) nanofiltration (NF) membranes in reclamation of wastewaters and treatment of industrial fluids. Herein, we introduced a facile and effective strategy for the modification of traditional PA-TFC NF membranes to improve water permeability and biofouling resistance. Specifically, three reactive guanidine molecules were successfully bonded onto the surface of PA-TFC membranes using chemical reactions between the amine groups of guanidine and the residual acyl chloride groups on the nascent PA-TFC membrane. The covalent attachment of guanidines can significantly enhance water permeability without compromising salt rejection. For instance, for 2 g L⁻¹ Na₂SO₄ aqueous solution, the water flux of NFM2 increased from 25.2 L m⁻² h⁻¹ to 68.4 L m⁻² h⁻¹ at 25 °C and 0.6 MPa compared to the traditional piperazine (PIP)–trimesoyl chloride (TMC) membrane, while around 98.3%. Na₂SO₄ rejection was maintained. Moreover, the membranes were endowed with easy-cleaning properties, which can remarkably prevent foulant adhesion, with the water flux recovery ratio being as high as 98.9%. The developed TFC membranes also showed excellent anti-adhesive and antimicrobial activities against Gram-negative Escherichia coli K12 (E. coli), Gram-positive Bacillus pumilus LDS33 (B. pumilus) and Aspergillus parasiticus JFS (A. parasiticus). Therefore, the resultant guanidinium-functionalized NF membranes which have integrated high permselectivity and superior fouling resistance properties are promising materials for fabricating a new generation of anti-fouling/antimicrobial surfaces that are applicable to many applications such as water desalination and softening and wastewater treatment.

As an emerging technology, forward osmosis (FO) has shown great promise in energy production from the mixing of fresh water and seawater in estuaries. However, the power density levels of the present commercial FO membranes hinder their practical applications in power generation due to the requirement for extremely large areas of membrane. Here, we use functionalized porous-single-layer graphene as a FO membrane and study the transport performances of the membrane using molecular dynamics simulation. For the FO system using fluorinated porous graphene (pore-diameter 11.7 Å, porosity 10%), with an excellent performance for salt rejection, the water flux is 28.1 L cm⁻² h which is about 1.8 × 10⁴ times higher than that of a typical cellulose triacetate membrane. Such high water flux will certainly bring about a very high power density in pressure retarded osmosis power generation. This work may generate potential opportunities for functionalized graphene in FO power generation, seawater desalination and so forth.

Reducing internal concentration polarization (ICP) and increasing water flux are essential for forward osmosis (FO) efficiency. Here, we use functionalized porous-single-layer graphene as a FO membrane and study its permeation properties via molecular dynamics simulations. Our results indicate that the ICP decreases to zero during FO processes, and that the water flux of graphene oxide reaches 91.5 L per cm² per day, which is about 1.7 × 10³ times higher than that of typical cellulose triacetate FO membranes. Furthermore, no forward or reverse solutes passing through the membrane are observed when the pore-diameter is smaller than 9.4 Å. This work may bring potential opportunities for functionalized porous graphene in water desalination, FO power generation and so forth.