Triboelectric nanogenerator (TENG) provides a new solution to the energy supply by harvesting high entropy energy. However, wearable electronic devices have high requirements for flexible, humidity-resistant, and low-cost TENG. Here, environment-friendly and multi-functional wheat starch TENG (S-TENG) was made by a simple and green method. The open-circuit voltage and short-circuit current of S-TENG are 151.4 V and 47.1 μA, respectively. S-TENG can be used not only to drive and intelligently control electronic equipment, but also to effectively harvest energy from body movements and wind. In addition, the output of S-TENG was not negatively affected with the increase in environmental humidity, but increased abnormally. In the range of 20% RH–80% RH, S-TENG can be potentially used as a sensitive self-powered humidity sensor. The S-TENG paves the way for large-scale preparation of multi-functional biomaterials-based TENG, and practical application of self-powered sensing and wearable devices.

Environmental deterioration, especially water pollution, is widely dispersed and could affect the quality of people's life at large. Though the sewage treatment plants are constructed to meet the demands of cities, distributed treatment units are still in request for the supplementary of centralized purification beyond the range of plants. Electrochemical degradation can reduce organic pollution to some degree, but it has to be powered. Triboelectric nanogenerator (TENG) is a newly-invented technology for low-frequency mechanical energy harvesting. Here, by integrating a rotary TENG (R-TENG) as electric power source with an electrochemical cell containing a modified graphite felt cathode for hydrogen peroxide (H₂O₂) along with hydroxyl radical (·OH) generation by Fenton reaction and a platinum sheet anode for active chlorine generation, a self-powered electrochemical system (SPECS) was constructed. Under the driven of mechanical energy or wind flow, such SPECS can efficiently degrade dyes after power management in neutral condition without any O₂ aeration. This work not only provides a guideline for optimizing self-powered electrochemical reaction, but also displays a strategy based on the conversion from distributed mechanical energy to chemical energy for environmental remediation.

Aybrid tribo/piezoelectric nanogenerators (HTPENG) have been proven to be highly efficient and versatile as far as the collection and conversion of ambient energy are concerned, and the introduction of flexible and green materials is a key step for their potential applications. Here, we developed a HTPENG by using nitrocellulose nanofibril paper as the triboelectric layer and BaTiO₃/MWCNT@bacterial cellulose paper as the piezoelectric layer. The output of the triboelelctric paper has considerable performance as fluorinated ethylene propylene, and the output of piezoelectric paper is more than ten times higher than the BTO/polydimethylsiloxane structure. The integrated outputs of the sandwich structured HTPENG are 18 V and 1.6 µA·cm^-2, which are capable of lighting up three LED bulbs and charging a 1 µF capacitor to 2.5 V in 80 s. In addition, the voltage signal generated by the HTPENG in contact-separation mode can be used for dynamic pressure detection. The linear range of dynamic pressure is from 0.5 to 3 N·cm^-2 with a high sensitivity of 8.276 V·cm²·N^-1 and a detection limit of 0.2 N·cm^-2. This work provides new insights into the design and application of cellulose-based hybrid nanogenerators with high flexibility and simple structure.

Anodic oxidization (AO) is one of the most important methods available for fabricating mesoporous Al₂O₃, which can be conducted at either high potential or low potential; however, the need for an external electricity power source limits its applications. In this work, a novel self-powered electrochemical anodic oxidization (SPAO) system was introduced for preparing mesoporous Al₂O₃, by using newly-invented triboelectric nanogenerator (TENG) arrays driven by wind power. Using the controllable voltage output of the TENG arrays, the SPAO system was shown to regulate the pore depth and pore size of the mesoporous Al₂O₃. In contrast to traditional AO systems, this technique takes advantage of the high output voltage of TENG arrays without any additional energy costs. In addition, the SPAO system can be used for the preparation of other mesoporous materials.