As an emerging energy-harvesting technology, enhancing the output performance of triboelectric nanogenerators (TENGs) is crucial for its practical application. Here, a dielectric enhancement effect is firstly proposed to improve the output performance of TENGs. It is found that the dielectric enhancement layer greatly elevates the triboelectrification effect, and the enhanced performance is verified by all types of TENGs. Thus, the output power of alternative current TENG (AC-TENG) and direct current TENG (DCTENG) realizes 8.5-fold and 2.6-fold enhancement of normal devices, respectively. Besides this, the dielectric enhancement layer with leakage performance is proven to be necessary for DC-TENG to produce a continuous output. Our work provides a simple and universal strategy for elevating the performance of all types of TENGs, which is beneficial to the promotion of large-scale energy harvesting by TENGs.

The emerging direct-current triboelectric nanogenerator (DC-TENG) does not need to be rectified and is not restricted by a dielectric breakdown compared with an alternating current TENG (AC-TENG). Furthermore, the charge density of the DC-TENG reaches an ultrahigh level far beyond that of the AC-TENG based on a rational design. However, there are always some electrons remaining on the surface of the dielectric after the breakdown process in the DC-TENG, and therefore a low charge utilization is obtained. Herein, a simple and universal method is proposed through a double-layer structure design, that is, a triboelectric layer as the friction layer and an electret layer charged through a surface treatment as the field-enhancing layer to further improve the output performance of the DC-TENG, which is inspired by the fable "The Crow and the Pitcher." Owing to the external field-enhancing breakdown effect, a double improvement in the breakdown efficiency and output charge density is obtained compared with a conventional DC-TENG. Moreover, a nearly constant output current has been demonstrated for directly powering electronics without a rectifier. This study provides a universal method for optimizing the output performance of a DC-TENG.

As a promising energy harvesters, triboelectric nanogenerators (TENG) can be utilized to convert distributed energy into electric power, but the slow charge accumulation incorporated with the inevitable charge decay/leakage of conventional TENGs result in a low surface charge density and an inferior output performance, limiting their practical applications. Here, an effective strategy is proposed to realize high charge density by using a fast charge accumulation process on dielectric material with high relative permittivity. As a result, the charge density is tremendously improved to 2.20 mC m −2 on the poly(vinylidene fluoride‐trifluoroethylene) film. Meanwhile, the fast charge accumulation is highly conducive to reach a high charge density of 1.30 mC m −2 in a 90% relative humidity environment, which is ≈260 times that of a TENG with slow charge accumulation. This work not only provides a new insight into charge accumulation and equilibrium state, but also provides significant guidance on the performance optimization of TENG.

With the excellent structural design, rotary triboelectric nanogenerator (R-TENG) is suitable for harvesting mechanical energy such as wind energy and water energy to build a self-powered electrochemical system for environmental science. The electrochemical performance has been greatly improved by using the pulsed direct-current (PDC) output of a TENG; however, a full-wave PDC (FW-PDC) is hardly realized in R-TENG devices due to existence of phase superposition. Here, a R-TENG with FW-PDC output is reported to perform a self-powered electro-Fenton system for enhancing the removal efficiency of levofloxacin (OFL). By adjusting the rotation center angle ratio between each rotator and stator unit, the phase superposition of R-TENG caused by multiple parallel electrodes can be effectively eliminated, thus achieving the desired FW-PDC output. Because of the reduced electrode passivation effect, the removal efficiency of OFL is improved by 30% under equal electric charges through using the designed R-TENG with FW-PDC output compared to traditional R-TENG. This study provides a promising methodology to improve the performance of self-powered electrochemical process for treating environment pollutions.

An ocean wave contains various marine information, but it is generally difficult to obtain the high-precision quantification to meet the needs of ocean development and utilization. Here, we report a self-powered and high-performance triboelectric ocean-wave spectrum sensor (TOSS) fabricated using a tubular triboelectric nanogenerator (TENG) and hollow ball buoy, which not only can adapt to the measurement of ocean surface water waves in any direction but also can eliminate the influence of seawater on the performance of the sensor. Based on the high-sensitivity advantage of TENG, an ultrahigh sensitivity of 2530 mV mm(-1) (which is 100 times higher than that of previous work) and a minimal monitoring error of 0.1% are achieved in monitoring wave height and wave period, respectively. Importantly, six basic ocean-wave parameters (wave height, wave period, wave frequency, wave velocity, wavelength, and wave steepness), wave velocity spectrum, and mechanical energy spectrum have been derived by the electrical signals of TOSS. Our finding not only can provide ocean-wave parameters but also can offer significant and accurate data support for cloud computing of ocean big data.