Arrieta Alvaro, Nuñez de la Rosa Yamid E, Pestana Samuel
Department of Biology and Chemistry, Universidad de Sucre, Sincelejo 700001, Colombia.
Faculty of Engineering and Basic Sciences, Fundación Universitaria Los Libertadores, Bogotá 111221, Colombia.
Molecules. 2024 Sep 3;29(17):4168. doi: 10.3390/molecules29174168.
The particular properties of graphene oxide (GO) make it a material with great technological potential, so it is of great interest to find renewable and eco-friendly sources to satisfy its future demand sustainably. Recently, agricultural waste has been identified as a potential raw material source for producing carbonaceous materials. This study explores the potential of cashew nut shell (CNS), a typically discarded by-product, as a renewable source for graphene oxide synthesis. Initially, deoiled cashew nut shells (DCNS) were submitted to pyrolysis to produce a carbonaceous material (Py-DCNS), with process optimization conducted through response surface methodology. Optimal conditions were identified as a pyrolysis temperature of 950 °C and a time of 1.8 h, yielding 29.09% Py-DCNS with an estimated purity of 82.55%, which increased to 91.9% post-washing. Using a modified Hummers method, the Py-DCNS was subsequently transformed into graphene oxide (GO-DCNS). Structural and functional analyses were carried out using FTIR spectroscopy, revealing the successful generation of GO-DCNS with characteristic oxygen-containing functional groups. Raman spectroscopy confirmed the formation of defects and layer separations in GO-DCNS compared to Py-DCNS, indicative of effective oxidation. The thermogravimetric analysis demonstrated distinct thermal decomposition stages for GO-DCNS, aligning with the expected behavior for graphene oxide. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) further corroborated the morphological and compositional transformation from DCNS to GO-DCNS, showcasing reduced particle size, increased porosity, and significant oxygen functional groups. The results underscore the viability of cashew nut shells as a sustainable precursor for graphene oxide production, offering an environmentally friendly alternative to conventional methods. This innovative approach addresses the waste management issue associated with cashew nut shells and contributes to developing high-value carbon materials with broad technological applications.
氧化石墨烯（GO）的特殊性质使其成为一种具有巨大技术潜力的材料，因此寻找可再生且环保的来源以可持续地满足其未来需求备受关注。最近，农业废弃物已被确定为生产含碳材料的潜在原料来源。本研究探索了腰果壳（CNS）这一典型的废弃副产品作为氧化石墨烯合成可再生来源的潜力。最初，对脱油腰果壳（DCNS）进行热解以生产含碳材料（Py-DCNS），并通过响应面法进行工艺优化。确定的最佳条件为热解温度950℃和时间1.8小时，得到29.09%的Py-DCNS，估计纯度为82.55%，洗涤后纯度提高到91.9%。随后，使用改进的Hummers方法将Py-DCNS转化为氧化石墨烯（GO-DCNS）。使用傅里叶变换红外光谱（FTIR）进行结构和功能分析，揭示了具有特征性含氧官能团的GO-DCNS的成功生成。拉曼光谱证实与Py-DCNS相比，GO-DCNS中形成了缺陷和层间分离，表明氧化有效。热重分析表明GO-DCNS有明显的热分解阶段，与氧化石墨烯的预期行为一致。扫描电子显微镜（SEM）和能量色散X射线光谱（EDX）进一步证实了从DCNS到GO-DCNS的形态和成分转变，展示了粒径减小、孔隙率增加和大量氧官能团。结果强调了腰果壳作为氧化石墨烯生产可持续前体的可行性，为传统方法提供了一种环境友好的替代方案。这种创新方法解决了与腰果壳相关的废物管理问题，并有助于开发具有广泛技术应用的高价值碳材料。
