Novel 3D Printed Vortex-like Flexible Roller-Compacted Triboelectric Nanogenerator for Self-Powered Electrochemical Degradation of Organic Contaminants

Design of high-performance modular triboelectric nanogenerators for efficient mechanical energy harvesting and electrochemical applications

Various forms of high-entropy energy (HEE), such as wind energy, ocean tidal energy, mechanical vibrations, and human motion, are widely distributed in nature and our surroundings. Effectively harvesting and utilizing these forms of energy has become a promising solution to address the challenges of sustainable energy development. Triboelectric nanogenerators (TENGs), with their unique advantages in harvesting low-frequency and micro-amplitude mechanical energy, have emerged as a key technology in the field of distributed energy systems and have attracted significant academic attention in recent years. However, to expand the application scenarios of TENGs, it is essential to continuously explore methods for improving their output performance. To meet the high-voltage output requirements of electrochemical applications, we developed a specialized electrochemical triboelectric nanogenerator (EC-TENG) by integrating a planetary gear-based mechanical structure with a multilayer parallel TENG configuration. This design significantly reduces the threshold for mechanical energy input while achieving a high-voltage output. By optimizing the rectification circuit, the crest factor was effectively reduced, and the current output was substantially enhanced. The EC-TENG demonstrated a maximum open-circuit voltage (VOC) of 575 V and a short-circuit current (ISC) of 42 μA, sufficient to power commercial electronic devices such as lamps. To enhance the portability and durability of the EC-TENG, a standardized manufacturing and packaging process was implemented, enabling quick replacement of vulnerable components and improving system reliability and service life. The EC-TENG shows great potential for high-voltage electrochemical applications, such as rust removal, and offers a sustainable and efficient solution for energy harvesting in distributed systems. This work provides a new perspective for addressing energy challenges and expanding the application scope of TENG-based technologies.

Triboelectric Nanogenerators for Self-Powered Degradation of Chemical Pollutants

Environmental and human health is severely threatened by wastewater and air pollution, which contain a broad spectrum of organic and inorganic pollutants. Organic contaminants include dyes, volatile organic compounds (VOCs), medical waste, antibiotics, pesticides, and chemical warfare agents. Inorganic gases such as CO2, SO2, and NO x are commonly found in polluted water and air. Traditional methods for pollutant removal, such as oxidation, physicochemical techniques, biotreatment, and enzymatic decomposition, often prove to be inefficient, costly, or energy-intensive. Contemporary solutions like nanofiber-based filters, activated carbon, and plant biomass also face challenges such as generating secondary contaminants and being time-consuming. In this context, triboelectric nanogenerators (TENGs) are emerging as promising alternatives. These devices harvest ambient mechanical energy and convert it to electrical energy, enabling the self-powered degradation of chemical pollutants. This Review summarizes recent progress and challenges in using TENGs as self-powered electrochemical systems (SPECs) for pollutant degradation via photocatalysis or electrocatalysis. The working principles of TENGs are discussed, focusing on their structural flexibility, operational modes, and ability to capture energy from low-frequency mechanical stimuli. The Review concludes with perspectives and suggestions for future research in this field, hoping to inspire further interest and innovation in developing TENG-based SPECs, which represent sustainable and eco-friendly solutions for pollutant treatment.

Stiffness Modulation in Flexible Rotational Triboelectric Nanogenerators for Dual Enhancement of Power and Reliability

Rotational nanogenerators with flexible triboelectric layers have wide applications and high reliability. However, flexible materials cause a severe reduction in contact force and thus triboelectric output power. Unlike previous works devising complex auxiliary structures to solve this issue, this paper focuses on improving the contact material mechanics and proposes a stiffness modulation method. By introducing fine patterns to the contacting rotor-stator pairs, the effective elastic modulus was regulated from approximately 103 to 105 MPa, and the output voltage was modulated from approximately 24.39% to 375.87% compared to the non-patterned rotor-stator pairs, corresponding to a maximal a 14 times increase in output power. A maximal power density of 18.75 W/m2 was achieved on 10 MΩ resistance at 9.6 Hz, which is even beyond the power density of most rigid triboelectric interfaces. Moreover, high reliability could be maintained when the volume ratio of the horizontal patterns exceeded a threshold value of 33.5% as the stator and 63.6% as the rotor for a 0.5 mm linewidth. These results prove the efficacy of the stiffness modulation method for jointly achieving high output power and high reliability in flexible rotational triboelectric nanogenerators.