Graphene is a novel material that has a single layer of carbon atoms. It has been used extensively in various technological applications [
1] that employ a variety of complex methods to adjust to each circumstance. Graphene is considered to be a promising nanomaterial for the prevention of corrosion [
2] because of its excellent chemical-stability, high specific-surface-area, and dominant-barrier properties. Up until now, the anticorrosion performance of metallized materials could be significantly increased with the reduction of defects and layers of graphene, which is supported by several reports [
3,
4]. For instance, Mogera et al. reported a simple method to create a protective layer of graphene on the surface of an Ni substrate [
5]; moreover, corrosion potential clearly increased and corrosion current density was conspicuously diminished compared with that of a naked substrate. Prasai et al. prepared a graphene layer on a Cu substrate via the chemical-vapor deposition method and observed that the corrosion medium was effectively impeded by the graphene coating [
6]. Ersan et al. researched the corrosive-protective mechanism of graphene [
7]. The mechanism indicated that the idiosyncratic structure of graphene was the main feature that protected the substrate from penetration by corrosive media. However, the sustainable period of graphene may be reduced because of galvanic corrosion [
1], even though studies demonstrated the superiority of graphene in corrosion protection [
8,
9]. Alternatively, to provide a better protective method, mixing the polymer matrix with graphene to form coatings in epoxy resin [
10,
11,
12] is advantageous because the composite mixture includes graphene’s outstanding barrier performance without the formation of an organic coating. Meanwhile, other attempts have been made to modify the surface of the coating through a range of different types of processing, including electrospinning [
13,
14], self-assembly [
15], sol-gel methods [
16,
17], and femtosecond laser processing [
18]. However, potential interlayer π–π interactions that are imposed on stacking between contiguous graphene nanosheets may result in low solubility of the solution [
19]. Currently, functionalized graphene is modified via various chemical reactions and interactions, such as covalent and noncovalent modification [
20], π–π stacking, and van der Waals or hydrogen bonding [
21]. However, the surface functionalization of graphene by using organic agents suffers from limited expandability and environmental problems. Moreover, adopting functionalization reagents could reduce the effectiveness of graphene and impede practical applications. By comparison with covalent chemical treatment [
22,
23], noncovalent physical treatment was a more appropriate method because it maintains the structural integrity, water dispersibility, and simple preparation of graphene. For example, Wu et al. employed π–π interactions by combining polypyrrole and graphene to obtain an excellent dispersive solution of graphene [
24]. Additionally, the corrosion rate of the metal substrate was effectively reduced by coating it with the hybrid composite [
25]. Chen et al. used interactions between MoS
2 and graphene to decrease the agglomeration of graphene in the solution and discovered that the defensive ability of the prepared coating was enhanced due to excellent dispersion [
26]. Hence, simultaneous reduction and functionalization is an optimal strategy for the preparation of graphene. However, the key point of durable preparation through noncovalent modification of well-dispersed graphene is still a challenge [
27,
28].
In order to solve the problems mentioned above, we present a method for preparing graphene with improved durability and surface functionalization via a one-step process. Tea polyphenols (TP) were simultaneously used as functionalization reagents, dispersants, and reductants [
29,
30]. These materials have outstanding water dispersibility and further improved the anticorrosion property of the coating. TP have a great deal of water-soluble polyphenols [
29], have low toxicity, and are biodegradable due to including epicatechin (EC), epicatechin gallate (ECG), and epigallocatechin (EGC) or epigallocatechin gallate (EGCG), except for in studies on antioxidant performance [
31]. Tea polyphenols have been employed as capping and reducing agents to combine with precious-metal nanoparticles [
30]. On the other hand, it has already been proven that hydrothermal treatment reduces graphene oxide (GO) to reduced graphene oxide (rGO) [
32,
33]. In view of its antioxidant abilities, water solubility, structural characteristics, and other applications in the affordable synthesis of graphene nanosheets, tea polyphenols that are used for the functionalization of graphene nanosheets impart outstanding water dispersibility and excellent corrosion-medium resistance performance. Next, we used X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) to characterize the structure, composition, and morphology of noncovalently functionalized graphene nanosheets. We also used electrochemical impedance spectroscopy (EIS) to investigate the anticorrosion ability of the coating in sodium chloride solution. Moreover, results indicated that graphene nanosheets that are synthesized via this method have satisfactory water-dispersibility properties by avoiding stacking, and excellent corrosion resistance in hostile environments.