[Triboelectric Nanogenerator]
Among various energy harvesters, the triboelectric nanogenerator (TENG) has attracted considerable attention due to its high instantaneous output power, broad selection of available materials, eco-friendly and inexpensive fabrication process, and various working modes customized for target applications. The TENG harvests electrical energy from wasted mechanical energy in the ambient environment.
Three types of operational modes based on contact-separation, sliding, and freestanding are studied for two different configurations with a double-electrode and a single-electrode structure in the TENGs. Various charge transfer mechanisms to explain the operational principles of TENGs during triboelectrification are also studied for electron, ion, and material transfers. Thereafter, diverse methodologies to enhance the output power considering the energy harvesting efficiency and energy transferring efficiency are surveyed.
In our lab, we focus on the solution of the following issues;
1) Highly Efficiency Power Generation
2) Sustainable and Stable Power Generation
3) Low Impedance Outputs
4) Battery-less Sensor
[Catalysts]
1) Large scale hydrogen production (2H2O -> 2H2 + O2)
At present, fossil energy is still our main source of energy, but the greenhouse effect and resource depletion are becoming increasingly severe. therefore, the development of a clean and abundant new energy source is urgent. Hydrogen energy is the cleanest energy source that has always attracted worldwide attention. Water splitting can produce hydrogen, which is one of the promising candidates obtained through clean and renewable method.
2) SCR De-NOx Catalyst (4NH3 + 4NO + O2 -> 4N2 + 6H2O)
Selective catalytic reduction with NH3 (NH3–SCR) is the most efficient technology to reduce the emission of nitrogen oxides (NOx) from coal-fired industries, diesel engines, etc. Although V2O5–WO3(MoO3)/TiO2 and CHA structured zeolite catalysts have been utilized in commercial applications, the increasing requirements for broad working temperature window, strong SO2/alkali/heavy metal-resistance, and high hydrothermal stability have stimulated the development of new-type NH3–SCR catalysts.
3) Gas sensor
As one of the most important devices to flammable, toxic and exhaust gases, a gas sensor provides a vital way to monitor the concentration and environmental information of gas towards safety. The cheap, reliable, small, and low-power-consuming gas sensors are in great demand due to the wide range of applications. With the increasing demand for better gas sensors of higher selectivity and sensitivity, rigorous efforts are in progress to find more suitable material with the required surface functionalization. we are focusing on the below-mentioned studies towards excellence in the gas sensing system.
[Light Absorption]
Recent development in autonomous vehicle technologies also continues to boost the growth of the IR market. Among the many applications of IR detectors, cost-effective night vision cameras, working in a wavelength range of 8 to 14 μm, are highly sought after for use in autonomous vehicles in order to identify pedestrians and wild animals during day and night, and even in strong direct sunshine, rainy or foggy conditions. The cooler-free microbolometers have a lot of advantages such as room temperature operation, low power consumption, and good portability due to low cost and light weight.
The key requirements of a highly responsive sensor with good detectivity are a high temperature coefficient of resistance (TCR) for the thermo-sensitive layer and high IR absorption. Low 1/f noise and thermal noise are also desirable characteristics, affected by the resistance of the TCR materials.
In our lab, we focus on the solution of the following issues;
1) Fabrication of microbolometer (Floating-type microbolometers, Semiconducting lithography )metal-
dielectric multilayer for high light absorption)
2) Phase control of Vanadate-based materials (Metal-insulator transition of VO2(M), highly-textured VO2(B) film, Defect-controlled phase growth)