With its light weight, low cost and high efficiency even at low operation frequency, the triboelectric nanogenerator is considered a potential solution for self-powered sensor networks and large-scale renewable blue energy. As an energy harvester, its output power density and efficiency are dictated by the triboelectric charge density. Here we report a method for increasing the triboelectric charge density by coupling surface polarization from triboelectrification and hysteretic dielectric polarization from ferroelectric material in vacuum (P ~ 10⁻⁶ torr). Without the constraint of air breakdown, a triboelectric charge density of 1003 µC m⁻², which is close to the limit of dielectric breakdown, is attained. Our findings establish an optimization methodology for triboelectric nanogenerators and enable their more promising usage in applications ranging from powering electronic devices to harvesting large-scale blue energy.

0D/2D heterojunctions, especially quantum dots (QDs)/nanosheets (NSs) have attracted significant attention for use of photoexcited electrons/holes due to their high charge mobility. Herein, unprecedent heterojunctions of vanadate (AgVO₃, BiVO₄, InVO₄ and CuV₂O₆) QDs/graphitic carbon nitride (g‐C₃N₄) NSs exhibiting multiple unique advances beyond traditional 0D/2D composites have been developed. The photoactive contribution, up‐conversion absorption, and nitrogen coordinating sites of g‐C₃N₄ NSs, highly dispersed vanadate nanocrystals, as well as the strong coupling and band alignment between them lead to superior visible‐light‐driven photoelectrochemical (PEC) and photocatalytic performance, competing with the best reported photocatalysts. This work is expected to provide a new concept to construct multifunctional 0D/2D nanocomposites for a large variety of opto‐electronic applications, not limited in photocatalysis.

The rapid development of Internet of Things and artificial intelligence brings increasing attention on the harvesting of distributed energy by using triboelectric nanogenerator (TENG), especially the direct current TENG (DC-TENG). It is essential to select appropriate triboelectric materials for obtaining a high performance TENG. In this work, we provide a set of rules for selecting the triboelectric materials for DC-TENG based on several basic parameters, including surface charge density, friction coefficient, polarization, utilization rate of charges, and stability. On the basis of the selection rules, polyvinyl chloride, used widely in industry rather than in TENG, is selected as the triboelectric layer. Its effective charge density can reach up to ~8.80 mC m⁻² in a microstructure-designed DC-TENG, which is a new record for all kinds of TENGs. This work can offer a basic guideline for the triboelectric materials selection and promote the practical applications of DC-TENG.

As a new-era of energy harvesting technology, the enhancement of triboelectric charge density of triboelectric nanogenerator (TENG) is always crucial for its large-scale application on Internet of Things (IoTs) and artificial intelligence (AI). Here, a microstructure-designed direct-current TENG (MDC-TENG) with rationally patterned electrode structure is presented to enhance its effective surface charge density by increasing the efficiency of contact electrification. Thus, the MDC-TENG achieves a record high charge density of ~5.4 mC m⁻², which is over 2-fold the state-of-art of AC-TENGs and over 10-fold compared to previous DC-TENGs. The MDC-TENG realizes both the miniaturized device and high output performance. Meanwhile, its effective charge density can be further improved as the device size increases. Our work not only provides a miniaturization strategy of TENG for the application in IoTs and AI as energy supply or self-powered sensor, but also presents a paradigm shift for large-scale energy harvesting by TENGs.

The rapid development of the Internet of Things and artificial intelligence has led to an increase in attention focused on distributed power sources such as triboelectric nanogenerators (TENGs), however, enhancing the energy output from TENGs is crucial for their large-scale application. Here, a constant-voltage TENG (CV-TENG) based on a phase-shift design is presented to enhance the energy output via converting a conventional pulse-voltage output into a constant-voltage one and decreasing the crest factor to 1.03. The average power is unexpectedly increased 1.9-fold compared with that of a pulse-voltage TENG (PV-TENG) without a phase-shift design. The energy enhancement is even more than 3-fold under a capacitance load in response to a low-frequency input. Furthermore, the dynamic process of charge transfer under a capacitance load is revealed, which gives a theoretical guide to improving the energy-output efficiency of a TENG toward 100%. This work provides a paradigm shift when it comes to achieving high-efficiency CV-TENGs, and it is of great importance for the acceptance of TENGs as a major form of energy technology.