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The emergence of tribovoltaic nanogenerators (TVNGs) paves the way for developing a new kind of semiconductor‐based energy harvester that overcomes the restriction of low output current in a conventional approach. The traditional TVNG generally depends on the frictional pair between two rigid semiconductors (or metal‐semiconductor), limiting the practicability of flexible and portable electronics. Recent developments require the fundamental understanding of charge generation in diverse operating modes and structures. Here, a flexible TVNG based on the p‐Cu2O/n‐g‐C3N4 interface is presented. Operating in a freestanding mode, the proposed TVNG can generate a stable signal in any optical conditions including UV illumination, dark, and ambient. Under UV illumination, the electrical outputs of the TVNG reach 0.43 V and 2.1 µA cm−2, which are significantly larger than those obtained from dark and ambient conditions. The results demonstrate the coupling effect of three phenomena: tribovoltaic, photovoltaic, and triboelectric effects, and the unique mechanism to the observed signal is proposed. Additionally, the TVNG shows the practical feasibility of energy harvesting with capacitor charging and charge‐boosting circuits. This study showcases the unique concept with potential for developing a novel flexible nanogenerator in many aspects, including material, structure, and fundamental mechanism. [ABSTRACT FROM AUTHOR]

There is a need to develop inexpensive, lightweight, and flexible high‐performance triboelectric nanogenerators (TENGs) from renewable resources. Here, a multifunctional cellulose filter paper (CFP)‐based TENG consisting of dielectric Ti0.8O2 nanosheets (Ti0.8O2 NSs) and conducting Ag nanoparticles (Ag NPs) is prepared by a simple dip coating method. The incorporation of dielectric Ti0.8O2 NSs onto the CFP significantly improves charge generation, while the inclusion of Ag NPs provides an electrically conductive path for charge transportation. The presence of these fillers can be deduced from XRD, SEM, EDS, X‐ray photoelectron spectroscopy, and Raman spectroscopy. Their distribution is visualized in 3D by synchrotron radiation X‐ray tomography. The present CFP‐based TENG provides an output voltage and current density of ≈42 V and ≈1 µA cm−2, respectively with the power density of ≈25 µW cm−2. It is capable of lighting up 40 light‐emitting diode bulbs and charging a 0.22 µF capacitor to 8 V in only 5 s. The developed TENG is also capable of detecting simple human motions, i.e., finger tapping, finger rubbing, and foot trampling. This work offers a facile design of low cost yet efficient paper‐based TENG by dual modification with multifunctional nanomaterials, and also demonstrates its use as a feasible power source that not only drives small electronics, but also scavenges energy from human actions. [ABSTRACT FROM AUTHOR]

Silver (Ag)/silver chloride (AgCl) nanoparticles have been used worldwide for their antimicrobial activity. Proteases play an important role in many physiological processes during wound healing. Therefore, the aim of this study was to fabricate silver-type nanoparticles exhibiting protease activity for medical applications such as wound healing and dressings. The Ag/AgCl nanoparticles were fabricated using Bacillus sp. protease and visible light activation. The size of the fabricated nanoparticles was estimated to be 35.29 ± 6.43 nm. The nanoparticles were coated on a cotton gauze bandage using immersion and ultrasonication. Scanning electron microscopy and energy dispersive X-ray spectroscopy confirmed that the nanoparticles could be used to coat the gauze bandage. Synchrotron radiation X-ray tomographic microscopy indicated that coating with the nanoparticles did not destroy the packing of cotton fibers in the gauze bandage. The nanoparticles exhibited fibrinolytic and collagenolytic activities. Protease activity remained after the nanoparticle coating was applied to the gauze bandage. The nanoparticles were not absorbed on a gelatin agar plate after incubation at 37 °C for 18 H. These results suggest that the coated cotton gauze bandage may be safe for further use, and the nanoparticles may not be absorbed into animal or human skin., (© 2020 International Union of Biochemistry and Molecular Biology, Inc.)