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The high‐efficiency conversion of water drop mechanical energy into electrical energy has always been an urgent issue in the development and utilization of raindrop energy. In this work, a novel drum‐like triboelectric nanogenerator (D‐TENG) with robust self‐cleaning superhydrophobic features is developed to harvest water drop energy. An elastic superhydrophobic cellulose paper is created by spray‐coating nanofumed silica dispersed in a thermoplastic elastomer solution, followed by treatment with triethoxy‐1H,1H,2H,2H‐tridecafluoro‐n‐octylsilane. When raindrops hit the D‐TENG surface, the superhydrophobic cellulose paper will vibrate and periodic contact and separation with polytetrafluoroethylene will occur to generate electricity. The results demonstrate that when a 6 mm water drop falls from a height of 2.5 m and hits the D‐TENG, the generated voltage output can reach a peak of 21.6 V and charge transfer of 10 nC. The output power of the D‐TENG can reach 16 µW per droplet, which is more than 13.3 times that generated from the previous TENGs based on the electrostatic induction of water droplets. These results indicate that the superhydrophobic cellulose paper‐based D‐TENG is potentially a strong candidate for harvesting energy from raindrops, thereby making it a promising sustainable energy source for next‐generation electronics. [ABSTRACT FROM AUTHOR]

[Display omitted] Triboelectric nanogenerators (TENGs), as a new energy conversion device in self-powered sensing devices, have been used at extreme environmental conditions, which poses great challenges to the structural stability and chemical tolerance of triboelectric materials. However, the low tolerance characteristics of traditional triboelectric materials limit their expansion in emerging applications. Cellulose, with its unique multidimensional structure and, controlled surface chemistry regulation advantages, shows great potential in resisting extreme environmental conditions and is emerging as a new candidate. This review aims to design and fabricate cellulosic triboelectric materials with exceptional tolerance, providing a perspective on the emerging applications of TENGs at extreme environmental conditions. First, the performance advantages and design principles of action of cellulosic triboelectric materials at extreme environmental conditions are described. Second, the importance of physical and chemical regulation strategies is discussed through the multi-scale perspective from macroscopic fiber bundles to microscopic cellulose molecules. It also presents the latest applications of cellulosic triboelectric materials at extreme environmental conditions such as wide temperature, high humidity, high corrosion, and radiation. Finally, the idea of how cellulosic triboelectric materials can further expand the development of TENGs application areas is presented. [ABSTRACT FROM AUTHOR]

The rapid rise of triboelectric nanogenerators (TENGs), which are emerging energy conversion devices in advanced electronics and wearable sensing systems, has elevated the interest in high‐performance and multifunctional triboelectric materials. Among them, cellulosic materials, affording high efficiency, biodegradability, and customizability, are becoming a new front‐runner. The inherently low dielectric constant limits the increase in the surface charge density. However, owing to its unique structure and excellent processability, cellulose shows great potential for dielectric modulation, providing a strong impetus for its advanced applications in the era of Internet of Things and artificial intelligence. This review aims to provide comprehensive insights into the fabrication of dielectric‐enhanced cellulosic triboelectric materials via dielectric modulation. The exceptional advantages and research progress in cellulosic materials are highlighted. The effects of the dielectric constant, polarization, and percolation threshold on the charge density are systematically investigated, providing a theoretical basis for cellulose dielectric modulation. Typical dielectric characterization methods are introduced, and their technical characteristics are analyzed. Furthermore, the performance enhancements of cellulosic triboelectric materials endowed by dielectric modulation, including more efficient energy harvesting, high‐performance wearable electronics, and impedance matching via material strategies, are introduced. Finally, the challenges and future opportunities for cellulose dielectric modulation are summarized. [ABSTRACT FROM AUTHOR]

Highlights: This review systematically discusses the interfacial properties of cellulosic material preparation processes, top-down, bottom-up, and composite processes. The rational design strategies of cellulosic triboelectric materials are summarized in detail, and the effects of different design strategies on the surface charge characteristics and charge density of cellulosic triboelectric materials are discussed. A comprehensive review of the research progress of cellulosic triboelectric nanogenerators in the field of self-powered wearable electronics. With the rapid development of the Internet of Things and flexible electronic technologies, there is a growing demand for wireless, sustainable, multifunctional, and independently operating self-powered wearable devices. Nevertheless, structural flexibility, long operating time, and wearing comfort have become key requirements for the widespread adoption of wearable electronics. Triboelectric nanogenerators as a distributed energy harvesting technology have great potential for application development in wearable sensing. Compared with rigid electronics, cellulosic self-powered wearable electronics have significant advantages in terms of flexibility, breathability, and functionality. In this paper, the research progress of advanced cellulosic triboelectric materials for self-powered wearable electronics is reviewed. The interfacial characteristics of cellulose are introduced from the top-down, bottom-up, and interfacial characteristics of the composite material preparation process. Meanwhile, the modulation strategies of triboelectric properties of cellulosic triboelectric materials are presented. Furthermore, the design strategies of triboelectric materials such as surface functionalization, interfacial structure design, and vacuum-assisted self-assembly are systematically discussed. In particular, cellulosic self-powered wearable electronics in the fields of human energy harvesting, tactile sensing, health monitoring, human–machine interaction, and intelligent fire warning are outlined in detail. Finally, the current challenges and future development directions of cellulosic triboelectric materials for self-powered wearable electronics are discussed. [ABSTRACT FROM AUTHOR]

The properties of materials play a significant role in triboelectric nanogenerators (TENGs). Advanced triboelectric materials for TENGs have attracted tremendous attention because of their superior advantages (e.g., high specific surface area, high porosity, and customizable macrostructure). These advanced materials can be extensively applied in numerous fields, including energy harvester, wearable electronics, filtration, and self‐powered sensors. Hence, designing triboelectric materials as advanced functional materials is important for the development of TENGs. Herein, the structural modification methods based on electrospinning to improve the triboelectric properties and the latest research progress in this kind of TENGs are systematically summarized. Preparation methods and design trends of nanofibers, microspheres, hierarchical structures, and doping nanomaterials are highlighted. The factors influencing the formation and properties of triboelectric materials are considered. Furthermore, the latest progress on the applications of TENGs is systematically elaborated. Finally, the challenges in the development of triboelectric materials are discussed, thereby guiding researchers in the large‐scale application of TENGs. [ABSTRACT FROM AUTHOR]

Synthetic polymer materials such as paraformaldehyde and polyamides are widely used in the field of energy engineering. However, they pose a challenge to environmental sustainability because they are derived from petrochemicals that are non‐renewable and difficult to degrade in the natural environment. The development of high‐performance natural alternatives is clearly emerging as a promising mitigation option. Inspired by natural bamboo, this research reports a "three‐step" strategy for the large‐scale production of triboelectric materials with special nanostructures from natural bamboo. Benefiting from the special hierarchical porous structure of the material, Bamboo/polyaniline triboelectric materials can reach short‐circuit current of 2.9 µA and output power of 1.1 W m–2 at a working area of only 1 cm2, which exceeds most wood fiber‐based triboelectric materials. More importantly, it maintains 85% energy harvesting after an extreme environment of high temperature (200 °C), low temperature (−196 °C), combustion environment, and multiple thermal shocks (ΔT = 396 °C). This is unmatched by current synthetic polymer materials. This work provides new research ideas for the construction and application of biomass structural materials under extreme environmental conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] Triboelectric properties of materials play an essential role in liquid energy harvesting and emerging application. The triboelectric properties of materials can be controlled by chemical functionalization strategy, which can improve the utilization of liquid energy resources or reduce the hazards of electrostatic effects. Herein, the latest research progress in molecular modification based on chemical functionalization to control triboelectric properties of materials is systematically summarized. By introducing the mechanism of contact electrification between liquid and solid materials and the developmental history of liquid–solid contact electrification, the influence of solid surface charge density, wettability and liquid properties on contact electrification of liquid and solid materials is described. Research progress on chemical functionalization for improving the hydrophobicity of solid materials, surface charge density of solid materials and triboelectric properties of liquid materials is highlighted. The focus then turns to the significance of enhanced liquid–solid contact electrification in energy harvesting, self-powered sensors and metal corrosion protection. Recent advances in chemical functionalization strategies for weakening the triboelectric properties of solid and liquid materials are also highlighted. Finally, an outlook of the potential challenges for developing chemical functionalization strategies in the field of solid surface modification and liquid molecular modification is presented. [ABSTRACT FROM AUTHOR]

[Display omitted] • Developing a superhydrophobic triboelectric material. • Designing a triboelectric nanogenerator with an internal grid structure. • It can collect distributed energy and exhibit excellent output performance. The development of triboelectric nanogenerators (TENGs) has made it possible to collect large-scale distributed energy, and their applications in the field of energy harvesting are promising. However, the erosion of water molecules in humid environments is a major challenge limiting the application of triboelectric materials. In this study, superhydrophobic methylated cellulosic triboelectric materials were prepared and rectangular TENG with an internal grid structure was designed for distributed energy harvesting. Interfacial modification of the cellulose nanofibrils (CNF) surface by silica nanoparticles to form a nanoscale microstructured surface further enhances the hydrophobicity of the triboelectric material. It was found that the modified CNF triboelectric material has excellent super-hydrophobicity (WCA: 154.7°), surface roughness (RMS: 72.61), and low surface energy. In addition, the RT-TENG internal grid structure is designed to allow external impact forces to be applied more uniformly to the surface of the f triboelectric material, demonstrating excellent electrical output performance (120 V) and cycling stability (10,000 cycles) when applied to distributed energy harvesting. This study provides a novel strategy for the design and preparation of superhydrophobic triboelectric materials and guides the study of distributed energy harvesting. [ABSTRACT FROM AUTHOR]