Authors: Ghazaleh Ramezani | Theo G. M. van de Ven | Ion Stiharu
Source: Recent Progress in Materials (article, 2025-01-21)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Novel In-Situ Synthesis Techniques for Cellulose-Graphene Hybrids: Enhancing Electrical Conductivity for Energy Storage Applications This study investigates the hypothesis that diverse synthesis techniques can yield cellulose-graphene hybrids with tailored properties for specific applications, enabling advancements in flexible electronics, energy storage, environmental remediation, and biomedical devices. We examined and compared multiple synthesis methods, including chemical reduction, in-situ synthesis, green synthesis using natural reducing agents, solvent-assisted approaches, hydrothermal and solvothermal techniques, mechanical and chemical treatments, and electrochemical exfoliation. Each method was assessed for its impact on material properties, scalability, and environmental footprint. Chemical reduction and in-situ synthesis resulted in uniform graphene dispersion and superior electrical conductivity, with the I(D)/I(G) ratio in Raman spectra indicating successful reduction of graphene oxide (GO) to reduced graphene oxide (rGO). Green synthesis, particularly using cow urine as a reducing agent, provided an eco-friendly alternative, leveraging its natural constituents to reduce GO to rGO while minimizing environmental impact. Mechanical and chemical treatments effectively prepared cellulose microfibers for compatibility with graphene, enhancing interfacial interactions and stress transfer in the resulting composites. Solvent-assisted techniques allowed precise tuning of composite properties through the selection of appropriate solvents and processing conditions. Hydrothermal and solvothermal methods produced hybrids with high purity and uniformity under high-temperature and high-pressure conditions, facilitating the reduction of GO to rGO and promoting strong bonding between cellulose and graphene. Electrochemical exfoliation generated high-quality graphene with controlled characteristics, allowing it to produce graphene with fewer defects compared to other methods. Findings reveal that cellulose-graphene hybrids synthesized using these methods exhibit significant improvements in thermal stability, electrical conductivity, and mechanical strength. For instance, even low rGO additions (3 wt%) surpassed the percolation threshold, resulting in electrical conductivity of 1.9 × 10&lt;sup&gt;-5&lt;/sup&gt; S cm&lt;sup&gt;-1&lt;/sup&gt; for cellulose/rGO (8 wt%) aerogels. These enhanced properties underscore the importance of carefully selecting synthesis techniques to optimize material characteristics for target applications. The research provides a comprehensive understanding of synthesis-method-property relationships, offering valuable insights for the development of advanced cellulose-graphene hybrid materials and highlighting their transformative potential across various high-impact fields, including flexible electronics, energy storage devices, environmental remediation systems, and biomedical applications. Graphene ; In situ ; Materials science ; Cellulose ; Conductivity ; Energy storage ; Nanotechnology ; Chemical engineering ; Chemistry ; Engineering ; Physics ; Organic chemistry Supercapacitor Materials and Fabrication ; Advancements in Battery Materials ; Graphene research and applications