Triboelectric nanogenerators (TENGs) are limited by poor charge retention and unstable output. This study investigates the effect of graphene oxide (GO) incorporation and environmental humidity on a nylon/polysiloxane-based TENG. Structural and chemical properties were analyzed using XRD, Raman, and FTIR, while SEM and photoluminescence (PL) were used to examine morphology and charge-trapping behavior. Electrical performance was evaluated through dielectric and TENG output measurements. An optimal GO loading of 0.05 wt
This study explores synthesizing and characterizing LaPO4:Sb3+/xMn2+ (LSBMx) phosphors (x = 0%-5%) prepared via the co-precipitation method. Structural analysis and luminescence properties reveal that LSBM0 (without Mn2+) emits blue light under UV excitation, while Mn2+-doped samples exhibit tunable emission from blue to orange-red. Under UV excitation, LSBMx phosphors demonstrate a broad visible emission band with multiple peaks attributed to the 4T1(4G) -> 6A1(6S) transition of Mn2+. The broad emission band (520-660 nm) can be deconvoluted into four Gaussian components centered at 564 nm (Mn-I), 595 nm and 616 nm (Mn-II), and 648 nm (Mn-III), corresponding to Mn2+ in La3+sites due to charge inconsistency, crystal field modifications induced by Sb3+ incorporation, and Mn2+- Mn2+ dimers, respectively. Energy transfer efficiency calculations determine the optimal Mn2+ concentration to be approximately 3%. This novel phosphor system demonstrates versatile green, orange, and red emission capabilities, establishing a valuable framework for developing Mn2+-doped luminescent materials with potential applications in LED lighting technology.
ZnO is recognized as one of the most versatile semiconductor materials, due to its adjustable properties, making it ideal for various applications. Herein, C-doped ZnO nanoparticles were obtained by thermal decomposition and tested as photocatalysts for water depollution and electrode materials in a symmetric supercapacitor device. These nanoparticles exhibited polyhedral shapes with sizes ranging from 95 to 104 nm. The impact of the doping level on the evolution of defect centers was analyzed using EPR and PL spectroscopy. Under visible light, the photocatalytic performance was tested against two contaminants, Rhodamine B (RhB) dye and oxytetracycline (OTC) antibiotic. A 1% C doping level provided the optimal photocatalytic performance, achieving degradation rates of 80% for RhB and 50% for OTC. The photodegradation process was elucidated by examining ROS species generated, linked to the measured valence band position and defect levels. Additionally, the same sample showed superior electrochemical performance when tested in a symmetric supercapacitor device, achieving a maximum specific capacitance of 104.16 F/g at a 2 mV/s scan rate, with an energy density of 14.46 Wh/kg and excellent cyclic stability, retaining 99% capacity after 2000 cycles. These findings highlight the versatility of C-doped ZnO nanoparticles, making them effective in environmental remediation and energy storage applications.
Introduction:This study examines the effect of multi-walled carbon nanotube (MWCNT) loading on the dielectric behavior and triboelectric performance of polysiloxane (PS)-based nanocomposites for high-efficiency triboelectric nanogenerators (TENGs). Methods:Flexible PS/MWCNT films were fabricated using the doctor blading method and characterized by Raman spectroscopy and scanning electron microscopy (SEM). Broadband dielectric spectroscopy was employed to analyze frequency-dependent permittivity, interfacial polarization, and dielectric loss. TENGs were assembled in a vertical contact-separation mode using nylon as the positive triboelectric layer and evaluated under controlled temperature and humidity. Statistical error analysis (n = 3) was applied to ensure quantitative reliability. Results:A co-optimal MWCNT concentration of 0.03-0.05 wt% enhanced dielectric permittivity and interfacial charge trapping, improving triboelectric output while keeping conductive losses low. Higher loadings led to nanotube aggregation and increased dielectric loss, degrading device performance. Discussion/Conclusion:The study establishes a quantitative correlation between dielectric spectroscopy and triboelectric output, providing mechanistic insight into performance enhancement and degradation. This framework offers practical guidelines for designing PS-based nanocomposite TENGs for wearable electronics, self-powered sensors, and portable energy-harvesting applications.
Lithium borohydride (LiBH4) is a promising hydrogen storage material releasing 13.8 wt% H2 upon decomposition in lithium hydride and boron, significantly surpassing other complex hydrides. However, sluggish dehydrogenation kinetics still hinder the use for practical applications. The infiltration of LiBH4 into carbon nanoscaffolds has proved to be effective in improving the hydrogen absorption/desorption (a/d) kinetics. Further improvement of storage kinetics can be achieved by modification of the nanocarbon with dopant elements. The present work compares nanoporous carbon (C-MSU-H) and C-MSU-H doped either with 1 at% N or 1 at% Ni as the matrix for infiltration of LiBH4. The catalytic effect of nitrogen proved to be superior to that of nickel (keeping the same doping level) for improving the hydrogen a/d kinetics of LiBH4 infiltrated in doped C-MSU-H. X-ray photoelectron spectroscopy was used to detect the amount and chemical proximity of nitrogen in nanoporous carbon following the thermal treatment in ammonia flow. The morphology and porosity of doped C-MSU-H were investigated by X-ray diffraction, FTIR, TEM, and BET. Hydrogen a/d kinetics of LiBH4@C-MSU-H nanocomposites was investigated by a volumetric method. The desorption peak temperatures (measured at 2 °C min-1 rate) are 339 °C for the undoped LiBH4@C-MSU-H, 328 °C for the LiBH4@C-MSU-H doped with 1 at% Ni and 318 °C for the LiBH4@C-MSU-H doped with 1 at% N nanocomposites. The activation energies of hydrogen desorption for the investigated nanocomposites were obtained from Kissinger plots: 142.7 kJ mol-1 for undoped LiBH4@C-MSU-H, 123.8 kJ mol-1 for LiBH4@C-MSU-H 1 at% Ni and 119.5 kJ mol-1 for LiBH4@C-MSU-H 1 at% N nanocomposites. The catalytic effect on LiBH4 dehydrogenation due to N-doping of nanocarbons is discussed.
