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Nowadays, investigations based on nanotechnology undertake breakthroughs in many application areas such as manufacturing, materials, nanoelectronics, energy, biotechnology, medicine, information technology, and others. The excellent properties of graphene-based materials, which are crucial in a wide range of applications, continuously highlight this promising new compound. Among them is for example graphene oxide (GO). It is an oxidized form of graphene with oxygen functional groups (carboxyl, hydroxyl, carbonyl, and epoxy) in the carbon lattice. However, the oxidation of graphite to GO introduces defects into the carbon structure that result in significantly altered physio-chemical properties, which are in some applications undesirable. One way to overcome the difficulties is to consider reduced graphene oxide (rGO) with decreased oxygen content. Material has altered physicochemical properties such as optical and surface functionalities, originating predominantly from higher electron mobility. The present work addresses the synthesis of GO, and rGO by introducing a simple approach and provides structural, morphological, chemical, and physical analysis of the synthesized material. GO was prepared by chemical oxidation and exfoliation of graphite flakes (particle size ≤ 50 μm) using Hummer’s method. rGO was, on the other hand, prepared by the hydrothermal method. Fourier transforms infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and Raman spectroscopy were used to evaluate the characteristics of this already known material. Results show that GO and rGO synthesized by the presented method, exhibit properties suitable for a wide range of applications such as in supercapacitors, water purification, and also as composite materials in coatings and even solar cells.

Accelerated industrial development in recent years has a negative influence on the aquatic ecosystem. Pollutants such as pesticides, microplastics, persistent organic pollutants, and dyes are present. In several industries, including cosmetics, plastic, paper, textiles, and rubber, synthetic dyes are used to give color to the products. The massive scale of used synthetic dyes, which are chemically and thermally stable in water, represents a potential hazard to the environment. The photocatalytic removal/degradation and wastewater treatment under solar-like irradiation have their own limitations. It is necessary to solve major challenges to overcome the drawbacks of the conventional water treatment processes. In this research, the hybridized photocatalyst was successfully synthesized as a mixture of pure TiO2 particles, reduced graphene oxide (rGO), and graphitic carbon nitride (g-C3N4). The graphene oxide (GO) material was synthesized by Hummer's method using natural graphite flakes (particle size ≤ 50 µm). The bulk g-C3N4 was prepared by a simple pyrolysis procedure using urea as a precursor. The hybridised rGO/TiO2/g-C3N4 photocatalyst has been self-assembled through one-pot hydrothermally synthesis followed by an annealing treatment. The morphological and structural analysis of the fabricated photocatalysts have been analyzed by X- ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Photocatalytic experiments with solar-like irradiation were performed to evaluate the efficiency of the synthesized materials. Composites were used as photocatalysts in the degradation of dye Methylene blue (MB) dye in an aqueous medium at a pH of 5.9. In addition to the natural pH of the solution (5.9), four other pH values (3.3, 7.3, 10.5, and 12.5) were adjusted and the efficiency of MB degradation was studied. The synthesized rGO/TiO2/g-C3N4 hybrid shows higher photocatalytic activity than pure TiO2 particles, TiO2/rGO, and TiO2/g-C3N4 composites in the degradation of MB dye in an aqueous medium (10 mg/L) under solar-like irradiation. The obtained results show that the photocatalytic activity of TiO2 increases with a higher amount of added rGO and g-C3N4. The pH of the solution also affects the MB degradation rate. Therefore, the highefficient hybridised rGO/TiO2/g-C3N4 photocatalyst could have the potential for environmental remediation.