Navaneeth Madathil

Vanadium tetrasulfide (VS ₄ ) is explored as a tribopositive material to develop high-performance triboelectric nanogenerators for efficient energy harvesting and self-powered electronic applications.

The increasing demand for sustainable energy solutions has strengthened the search for new materials in triboelectric nanogenerator (TENG) design to improve output and device performance. Although several materials have been studied, the triboelectric series remains limited to a few classes, including oxides, 2D materials, MOFs, and polymers. Developing efficient, low‐cost electron donors offers new hope for improving TENG performance. Most studies focus on polymers or inorganic compounds, with limited exploration of organic molecules with strong electron‐donating or acceptor properties. The present manuscript focuses on phenothiazine (PTZ) and its derivative, N‐ethyl‐phenothiazine (NEt‐PTZ), as a new class of triboelectric positive material for the TENGs. Utilizing their conjugated aromatic frameworks and the electron‐donating nature of nitrogen and sulfur heteroatoms to improve charge transfer. A one‐step synthesis process for NEt‐PTZ demonstrated superior triboelectric performance compared to PTZ, producing an output of 450 V and 80 µA, owing to its enhanced electron‐donating properties. The device successfully powered wristwatches, calculators, and up to 400 LEDs, and exhibited stable operation over 10 000 mechanical cycles. This research not only broadens the triboelectric material library but also introduces a new category of dye‐based electron‐donating materials, offering a scalable and straightforward method to improve energy harvesting and self‐powered device applications.

Electronic waste (e‐waste) and the use of portable electronic devices are rapidly increasing due to technological advancements globally, leading to harmful effects on the environment. E‐waste causes severe environmental damage, such as the pollution of soil, water, and air. Therefore, there is an urge for effective e‐waste management, recycling, and sustainable consumption. In this report, We developed high‐performance triboelectric nanogenerators (TENGs) utilizing discarded laptop LCD screens as triboelectric layers for energy harvesting and organic dye pollutant degradation. Among all the fabricated devices, the LCDW4‐TENG exhibited exceptional performance with fluorinated ethylene propylene (FEP) as the opposite frictional layer, yielding a V_oc of ≈470 V, I_sc of ≈ 143 µA, and a power density of 5.04 W m⁻² at a load resistance of 1 MΩ. The long‐term stability of the device is tested over 6,000 cycles and is found to be very stable. This e‐waste‐based TENG is employed in the treatment of methylene blue organic dye through TENG‐assisted photocatalysis. An enhanced degradation efficiency of methylene blue dye is observed with the support of TENG. This work highlights the potential of LCD waste‐derived TENGs for driving self‐powered electronic devices and environmental remediation applications thereby contributing to the circular economy concept.

This study explores using metal–organic framework materials, notably MIL‐88 A and BaTiO₃, as multifunctional additives within polydimethylsiloxane to boost the performance of triboelectric nanogenerators (TENGs). This novel approach has significantly improved the TENG device's efficiency, making it an effective triboelectric layer. The developed TENG device produces an open‐circuit voltage, short‐circuit current, and maximum power density of 486 V, 160 μA, and 5.82 W m⁻², respectively. The fabricated TENG device is used to power 360 light emitting diodes and various self‐powered electronic devices. A unique feature of the study is the transformation of acoustic energy into electrical energy using the TENG device. A small‐sized TENG is attached to a loudspeaker's diaphragm, converting sounds from various musical instruments and animal noises into electrical signals. This capability opens up new avenues for harnessing ambient acoustic energy, a largely untapped resource.

In this manuscript, we present a novel approach for integrating Triboelectric Nanogenerators (TENGs) into signature stamps, termed Stamp TENG (S-TENG). We have modified a commercially available stamp holder to integrate triboelectric layers for multiple applications like effective energy harvesting, sensing, and embedded electronics for data prediction. S-TENG has been further explored in remote monitoring systems for elderly individuals and for gathering real-time statistics regarding persons or events at specific locations. The S-TENG is fabricated using FEP and Al as functional layers. It demonstrates an output voltage of 310 V, a current of 165 μA, and a power density of 14.8 W/m². The simplicity of the S-TENG’s design is noteworthy. Its ability to generate energy through simple, repetitive stamping actions, which anyone can perform without specialized training, stands out as a key feature. The device is also designed for ease of use, being handheld and user-friendly. Its flexible and adaptable structure ensures that individuals with varying physical capabilities can comfortably operate it. An impressive capability of the TENG is its ability to illuminate 320 LEDs with each stamp press momentarily. Furthermore, using energy management circuits, the S-TENG can power small electronic gadgets such as digital watches and thermometers for a few seconds. In addition, when integrated with electronics, the S-TENG shows great potential in data prediction for various practical applications.

In recent years, multifunctional applications of the same material have gained wide recognition in various fields. The present study reports the synthesis, characterization, and multifunctional applications of europium (Eu)‐doped yttrium oxide (Y₂O₃) nanophosphor. Synergistic optimization of Eu‐doped Y₂O₃ results in enhanced photoluminescence (PL) and triboelectric nanogenerator (TENG) performance. Eu‐doped Y₂O₃ nanophosphors are synthesized using an autocombustion method, and comprehensive characterizations are conducted. The investigations indicate that the Eu doping significantly influences the PL intensity, with the highest emission observed at 3 mol% for powders. The synthesized nanophosphors are blended with silicone to fabricate hybrid films, which are utilized for energy harvesting applications using TENG technology. The TENG devices fabricated with these hybrid films demonstrate a notable relationship between the Eu concentration and the electrical output, achieving peak performance at 1 mol% Eu doping. The maximum output voltage of ≈535 V, short‐circuit current of ≈38 μA, and power density of 800 mW m⁻² are observed. Further, TENG is demonstrated in a self‐powered UV photodetector application. The present results contribute to the improvement of sustainable energy technologies and open up a new window for multifunctional materials.