Seeking to increase the triboelectric charge density on a friction layer is one of the most basic approaches to improve the output performance of triboelectric nanogenerators (TENGs). Here, we studied the storage mechanism of triboelectric charge in the friction layer and discussed the function of carrier mobility and concentration in the charge-storing process. As guided by these results, a kind of composite structure is constructed in the friction layer to adjust the depth distribution of the triboelectric charges and improve the output performance of TENGs. To further elucidate this theory, a simple TENG, whose negative friction layer is a composite structure by integrating polystyrene (PS) and carbon nanotubes (CNTs) into polyvinylidene fluoride (PVDF), was fabricated, and its performance test was also carried out. Comparing with a pure PVDF friction layer, the composite friction layer can raise the triboelectric charge density by a factor of 11.2. The extended residence time of electrons in the friction layer is attributed to a large sum of electron trap levels from PS.

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Graphene oxide (GO) was introduced into carbon fiber/ epoxy composite using a wet process for impregnating carbon fiber by epoxy added with GO, which resulted in an enhancement in the interfacial performance and electromagnetic interference shielding effectiveness (SE) of composite. To investigate the reinforcing mechanism, we compared the reinforcing effect between graphene oxide and reduced graphene oxide through interlaminar shear strength test, microdrop test, scanning electron microscopy, and transmission electron microscopy. The results indicate that toughening effect plays the key role for the interfacial improvement of carbon fiber/graphene nanosheets/epoxy composite. By adding only 0.1 wt% GO, the composite achieved an 11% enhancement of interlaminar shear strength at the maximum of 117.45 MPa and a SE improvement about 10 dB in the range of 5-20 GHz in the meantime, giving rise to a highly practicable potential for industrial utilization.

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A film stripping method that allows for liquid phase exfoliation assisted by spin coating polymethyl methacrylate has been investigated, resulting in a two‐inch hexagonal boron nitride (hBN) film to be fully stripped and then transferred. A number of key factors that can influence the stripping and the transferring process of the films grown by sputtering have been systematically analyzed, including different solutions, different concentration of solution and different thickness of films. The morphology and properties of the hBN films before and after stripping have been characterized. The band edge absorption peak of the transferred film is 229 nm and the corresponding optical band gap is 5.50 eV. Such transferred hBN films have been fabricated into transparent resistive switching devices on indium‐tin‐oxide glass, demonstrating a constant resistance window of ≈102 even under different applied voltages. This work systematically studies the stripping process, characterizes the transferred films, and explores the application in the field of resistance switching, which lay a foundation for the further application of hBN materials in optoelectronic devices.