Economical synthesis and optimization for few layers graphene by solid carbon sources: domestic CVD technique

Abstract

Chemical vapor deposition (CVD) is widely regarded as an effective method for synthesizing high-quality graphene; however, its widespread industrial adoption is limited by high operational costs, complex instrumentation, and scalability challenges. In this study, we present a cost-effective and scalable approach for the synthesis of various graphene-based nanostructures, including few-layer graphene, carbon nanofibers, multilayer graphene (graphene islands), and flower-like graphene sheet morphologies, using a domestic CVD setup and a solid carbon source composed of a naphthalene/camphor mixture. The process optimization was guided by three critical parameters: precursor composition, the axial distance (δ) between the precursor and the substrate, and the carrier gas composition (Ar: H<inf>2</inf> ratio). Experimental results demonstrated that a precursor mixture containing 10 wt% naphthalene and 90 wt% camphor, positioned at a distance of δ = 25 cm from the substrate, and processed under an Ar: H<inf>2</inf> gas flow ratio of 9:1, yielded graphene with an I<inf>2D</inf> /I<inf>G</inf> intensity ratio of 0.6 in Raman spectra, indicative of few-layer graphene formation. High-resolution transmission electron microscopy (HRTEM) was employed to characterize the internal lattice structure of the deposited graphene, while scanning electron microscopy (SEM) provided insights into the surface morphology of the synthesized carbon nanostructures. Additionally, Fourier-transform infrared spectroscopy (FTIR) was utilized to identify surface functional groups associated with the deposited graphene. The outcomes of this study validate the feasibility of an economical and efficient solid-phase CVD method for producing few-layer graphene, offering promising potential for application in diverse engineering and technological domains. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2025.