Sardana Sagar, Sharma Vaishali, Beepat Kevin Gurbani, Sharma Davinder Pal, Chawla Amit Kumar, Mahajan Aman
Department of Physics, Guru Nanak Dev University, Amritsar, India.
Department of Physics, University of West Indies, St. Augustine, Trinidad and Tobago.
Nanoscale. 2023 Dec 7;15(47):19369-19380. doi: 10.1039/d3nr04537d.
The low surface-charge density, poor stability and irreparable surface of triboelectric materials under harsh environments are still some obstacles for developing high-performance triboelectric nanogenerators (TENGs). In particular, a two-dimensional MXene material's surface is likely to be corroded by water molecules under high humidity conditions owing to its hydrophilic nature, limiting the output performance and stability of TENGs. Herein, an approach for fabricating a humidity- and contamination-resistant MXene-based TENG is established using the electrospinning technique. First, nanofibrous layers of MXene/MoS composites blended in a cellulosic polymer matrix were prepared, benefitting the high surface roughness and controlled air-trapping pores. Furthermore, the prepared nanofibrous layers were chemically modified with stearic acid (SA), which enhances the hydrophobicity and electronegativity of MXene/MoS composites. In a typical synthesis, four different compositions of MXene/MoS/cellulose acetate nanofibers were prepared, which illustrates that an increasing concentration of MoS could effectively tune the surface oxidation, hydrophilic nature, and surface roughness of MXene as well as induce a piezoelectricity-enhanced triboelectric potential. On the other side, the SA modification ultimately generated a superhydrophobic surface with low surface energy and a high water contact angle of ∼154°. The integrated TENG displayed an enhanced output voltage of ∼140 V and an instantaneous power density of ∼2975 mW cm with long-term stability under high humidity conditions. Additionally, the self-cleaning properties were demonstrated, ensuring the sustainability and reusability of the TENG in a contaminated environment. Moreover, the fabricated MXene-based superhydrophobic layer can harvest the energy on dripping water droplets based on the liquid-solid contact-electrification TENG mode. Overall, this work paves the way for the design and development of humidity- and contamination-resistant triboelectric materials and guides the study of harvesting of distributed environmental energy efficiently.
摩擦电材料在恶劣环境下表面电荷密度低、稳定性差以及表面不可修复等问题，仍然是开发高性能摩擦纳米发电机（TENGs）的一些障碍。特别是，二维MXene材料的表面由于其亲水性，在高湿度条件下容易被水分子腐蚀，限制了TENGs的输出性能和稳定性。在此，利用静电纺丝技术建立了一种制备耐湿和抗污染的MXene基TENG的方法。首先，制备了在纤维素聚合物基体中混合的MXene/MoS复合材料的纳米纤维层，这有利于高表面粗糙度和可控的空气截留孔隙。此外，用硬脂酸（SA）对制备的纳米纤维层进行化学改性，增强了MXene/MoS复合材料的疏水性和电负性。在典型的合成中，制备了四种不同组成的MXene/MoS/醋酸纤维素纳米纤维，这表明MoS浓度的增加可以有效地调节MXene的表面氧化、亲水性和表面粗糙度，并诱导增强压电性的摩擦电势。另一方面，SA改性最终产生了具有低表面能和154°高水接触角的超疏水表面。集成的TENG在高湿度条件下显示出增强的输出电压140 V和瞬时功率密度~2975 mW/cm²，并且具有长期稳定性。此外，还展示了自清洁性能，确保了TENG在污染环境中的可持续性和可重复使用性。此外，制备的MXene基超疏水层可以基于液-固接触起电TENG模式收集滴水的能量。总体而言，这项工作为耐湿和抗污染摩擦电材料的设计和开发铺平了道路，并指导了高效收集分布式环境能量的研究。
