Cheong Jian Ye, Koay Jason Soon Chye, Gopal Sanjeev Raj, Velayutham Thamil Selvi, Gan Wee Chen
Low Dimensional Materials Research Center, Department of Physics, Faculty of Science, Universiti Malaya 50603 Kuala Lumpur Malaysia
Kelip-kelip! Center of Excellence for Light Enabling Technologies, School of Energy and Chemical Engineering, Xiamen University Malaysia Selangor Darul Ehsan 43900 Malaysia
Nanoscale Adv. 2024 Dec 9;7(3):819-829. doi: 10.1039/d4na00820k. eCollection 2025 Jan 28.
Incorporating carbon-based fillers into triboelectric nanogenerators, TENGs, is a compelling strategy to enhance the power output. However, the lack of systematic studies comparing various carbon fillers and their impact on tribopositive contact layers necessitates further research. To address these concerns, various carbon fillers (including buckminsterfullerene (C), graphene oxide (GO), reduced graphene oxide (rGO), multi-wall carbon nanotube (MWCNT), and super activated carbon (SAC)) with distinct structural and electrical properties are mixed with polyvinyl alcohol, PVA, to form PVA-carbon composites and used as tribopositive layers in the contact-separation of TENGs. The results show that PVA-SAC provides the largest enhancements to the electrical outputs of the TENG. At the optimal loading of 1 wt%, PVA-SAC composites yielded a peak power density of 12.8 W m, a substantial 220% enhancement compared to pristine PVA. The mechanism governing the enhancement is determined by analysing the changes in electrical and structural characteristics caused by the addition of various carbon fillers. Dielectric measurements indicated that enhanced dielectric properties did not significantly contribute to the observed increase in the triboelectric performance. Instead, Raman and FTIR analyses revealed a correlation between the PVA-carbon interactions and an increase in the D/G ratio of carbon fillers, accompanied by a reduction in hydrogen-bonded -OH groups within PVA. This suggests that the interaction between the π electrons of sp hybridized carbon atoms and the oxygen lone pairs in PVA inhibits hydrogen bond formation, leading to an increase in free -OH groups. Consequently, these free -OH groups enhanced the electron-donating capability and improved the tribopositive behaviour of the PVA-carbon composites. Our results proved that filler-matrix interactions are paramount in engineering high-performance TENGs by controlling the electron affinity of the triboelectric layers.
将碳基填料融入摩擦电纳米发电机（TENGs）是提高功率输出的一种极具吸引力的策略。然而，目前缺乏对各种碳填料及其对摩擦正电接触层影响的系统研究，这需要进一步开展研究。为了解决这些问题，将具有不同结构和电学性质的各种碳填料（包括巴克敏斯特富勒烯（C）、氧化石墨烯（GO）、还原氧化石墨烯（rGO）、多壁碳纳米管（MWCNT）和超级活性炭（SAC））与聚乙烯醇（PVA）混合，形成PVA-碳复合材料，并用作TENGs接触-分离模式中的摩擦正电层。结果表明，PVA-SAC对TENG的电输出增强作用最大。在1 wt%的最佳负载量下，PVA-SAC复合材料产生的峰值功率密度为12.8 W/m²，与原始PVA相比大幅提高了220%。通过分析添加各种碳填料引起的电学和结构特征变化，确定了增强作用的机制。介电测量表明，增强的介电性能对摩擦电性能的显著提高贡献不大。相反，拉曼光谱和傅里叶变换红外光谱分析表明，PVA-碳相互作用与碳填料的D/G比增加之间存在相关性，同时PVA中氢键结合的-OH基团减少。这表明sp²杂化碳原子的π电子与PVA中的氧孤对之间的相互作用抑制了氢键形成，导致游离-OH基团增加。因此，这些游离-OH基团增强了供电子能力，改善了PVA-碳复合材料的摩擦正电行为。我们的结果证明，填料-基体相互作用对于通过控制摩擦电层的电子亲和力来设计高性能TENGs至关重要。
