Synthesis of novel nanocomposite of g-C3N4 coated ZnO–MoS2 for energy storage and photocatalytic applications

• Published in: Chemosphere (Oxford) Vol. 350; p. 141014
• Main Authors: Sahu, Dojalisa, Panda, Nihar Ranjan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2024
• Subjects: alizarin; capacitance; chemical composition; electrochemistry; energy; Energy storage; energy-dispersive X-ray analysis; g-C3N4@ZnO:MoS2; Heterojunction; Hybrid materials; methylene blue; microstructure; Nanocomposite; nanocomposites; nanoparticles; nanosheets; oxidation; Photocatalysis; photolysis; transmission electron microscopy; X-ray diffraction; X-ray photoelectron spectroscopy; g-C3N4@ZnO:MoS2; Nanocomposite; Hybrid materials; Photocatalysis; Heterojunction; Energy storage
• ISSN: 0045-6535; 1879-1298; 1879-1298
• DOI: 10.1016/j.chemosphere.2023.141014

Fabrication of heterostructures for energy storage and environmental remedial applications is an interesting subject of research that has been undertaken in this present investigation. The incorporation of g-C3N4 into ZnO:MoS2 heterojunction nanocomposite was accomplished by wet-chemical route and characterized by various techniques to ascertain its structure, morphology, and study its potential electro-optical characteristics. The g-C3N4@ZnO:MoS2 sample was investigated by x-ray diffraction (XRD) which reveals the co-existence of the ZnO, MoS2 and C3N4 phases linked to characteristic crystallographic planes in the spectrum, validating the formation of ternary nanocomposite. The XRD patterns of the pristine samples were also considered as reference to understand the structural evolution and phase transformations. Field emission scanning electron microscopy (FESEM) study states the formation of heterogeneous nanostructures having nanoparticles embedded on 2-D nanosheets like structures. Studies using energy dispersive spectroscopy (EDS) and elemental mapping show that all the elements that are linked to the above hybrid nanocomposite are present. Transmission electron microscopy (TEM) provided clear insights on the microstructure as we can identify the distribution of ZnO and MoS2 nanostructures on layered g-C3N4 nanosheets. The chemical composition and oxidation states of elements were elucidated by X-ray photoelectron spectroscopy (XPS) study, which added another layer of confirmation on the structural evolution of the ternary nanocomposite. Fourier transformed infrared (FTIR) study revealed the layered structure of sp2 hybridized bonding features of C and N in g-C3N4, besides Zn–O and Mo–S stretching vibrations. The nanocomposite demonstrated improved photodegradation efficacy and decomposed alizarin red and methylene blue dyes significantly with better stability and reusability. MoS2 as a co-catalyst acts as an electron acceptor/accelerator in the Z-scheme composite photocatalysis leading to improved photocatalytic efficiency. The resulting heterostructured material delivered a higher specific capacitance of 10.85 F/g with good capacitance retention. Electrochemical study revealed the energy storage capability of the hybrid system. [Display omitted] •Preparation of ternary hybrid nanocomposites for photocatalytic and energy harvesting.•HRTEM shows formation of heterojunction of ZnO–MoS2 on g-C3N4 nanosheets.•MoS2 serves as an electron accelerator in the Z-scheme photocatalytic process.•Delay in carrier recombination and promotion of OH.• radical formation resulting enhanced degradation•Superior energy storage features of the nanocomposite.