Self-powered sensors are crucial in the field of wearable devices and the Internet of Things (IoT). In this paper, an organ-like Ti 3 C 2 T x MXene/metal−organic framework-derived copper oxide (CuO) gas sensor was powered by a triboelectric nanogenerator (TENG) based on latex and polytetrafluoroethylene for the detection of ammonia (NH 3 ) at room temperature. The peak-to-peak value of open-circuit voltage and short-circuit current generated by the prepared TENG can reach up to 810 V and 34 μA, respectively. The TENG can support a maximum peak power density of 10.84 W• m −2 and light at least 480 LEDs. Moreover, a flexible TENG under a single-electrode working mode was demonstrated for human movement stimulation, which exhibits great potential in wearable devices. The self-powered NH 3 sensor driven by TENG has an excellent response (V g /V a = 24.8 @ 100 ppm) at room temperature and exhibits a great potential in monitoring pork quality. Ti 3 C 2 T x MXene and CuO were characterized by SEM, TEM, EDS, XRD, and XPS to analyze the properties of the materials. The NH 3 sensing performance of the self-powered sensor based on MXene/CuO was greatly improved, and the mechanism of the enhanced sensing properties was systematically discussed. KEYWORDS: self-powered sensor, triboelectric nanogenerator, Ti 3 C 2 T x MXene, NH 3 sensor, flexible electronics

Nickel nanospheres, nanowires, and nanoflowers are synthesized via a facile non‐aqueous sol–gel route involving the reaction of nickel acetylacetonate with benzyl alcohol at 200 °C in the presence of varying magnetic fields, as illustrated in the figure. Benzyl alcohol acts as both the solvent and reductant in this system. The nanostructures show substantial enhancement in coercivity as compared to bulk nickel.

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The gradients of root exudates and of persistent organic pollutants, including polycyclic aromatic hydrocarbons (PAHs), in rhizosphere soil in proximity to the root surface are still not well elucidated. In this work, a greenhouse experiment was conducted to investigate the distribution gradients of root exudates and phenanthrene and pyrene, as selected PAHs, in rhizosphere soil close to (0-8 mm) the root surface of ryegrass [Ldium multiflorum Lam.) as the host plant. Rhizosphere soil from the root surface (0-8 mm) was divided into three layers: the rhizoplane and strongly and loosely adhering soil. Root exudates were characterized as soluble organic C, organic acids, and total soluble sugars. In PAH-spiked rhizosphere soils, the concentration of root exudates decreased with distance from the roots. In a sterilized treatment, the amounts of root exudates in the three rhizosphere layers were higher than when the soil was not sterilized, indicating that microbial consumption contributed significantly to the loss of root exudates in the rhizosphere. Tlie residual concentrations of phenanthrene and pyrene clearly increased in die order of rhizoplane to loosely adhering soil after 40 to 50 d, which was significantly and negatively correlated with the amount of root exudates in the rhizosphere. In total, 87 to 97% of phenanthrene and 69 to 79% of pyrene dissipated in all three layers of rhizosphere soil after 40 d, and >99% of phenanthrene and 93% of pyrene dissipated after 50 d. The degradation ratio of PAHs decreased in rhizosphere soils with distance from the roots.Abbreviations: OA, organic acid; PAH, polycyclic aromatic hydrocarbon: SOC, soluble organic carbon: TSS,) total soluble sugar.