Hydrogen Fuel

Now-a-days, the global energy demand is met through fossil fuels, hydropower, and nuclear energy sources. However, the faster depletion of fossil fuels, its increasing demand, and reducing supply increase the cost of oil and natural gas at a rapide rate. The result will be the scarcity of automobile fuel in the world which will create a lot of preblems in the transport sector. The other aspect is emission of greenhouse gases through the combustion of fossil fuels is a matter of concern from the environmental point of view. There is a constant search for alternate energy sources to solve energy sources with pollution-free. Hydrogen is amost promissing, and an alternative source of energy, which can replace the existing fossil fuels because of its clean, efficient, eco-friendly, light weight, high energy density, and easy storage. Hydrogen will be useful for the generation of electricity, cooking food, as fuel for automobiles etc. Hydrogen fuel has been tested experimentally for cars and many major car companies are building commercial hydrogen fuel automobiles soon at a higher cost and is expected to decrease the cost of hydrogen cars. Recently, chalcogenides-based semiconductor photocatalysts such as Bi2S3, SnS2, Sb2S3, AgSbS2, CuSbS2, CuPbSbS3 etc., have emerged as promising materials for H2 production owing to their appropriate band gaps, non-toxicity, and chemical stability. Various methods can be used to prepare these semiconductor photocatalysts for H2 production. In the proposed research we would like to fabricate these chalcogenide-based photocatalysts by chemical bath depsotion (CBD), thermal evaporation and sputtering techniques.

 To address this issue, we introduced and developed the concept of a probing wafer. This is a technology that can measure the electrical characteristics of all individual micro LED chips in an on-wafer state with a single voltage application by contacting the probing wafer to the LED wafer in the form of a flip chip. The possibility of our proposed method was demonstrated through the luminescence inspection and measurement of electrical characteristics of a micro LEDs cell unit by using the probing wafer. 

Super Capacitor

Over the past few decades, the rapid consumption fossil fuel resources and its impact on environment has given tremendous importance to the development of high-efficiency and renewable energy storage systems (ESS) for compace electronic devices, electric vehicles, and smart grids. In this context different rechargeable technologies, such as solar cells, secondary batteries, and supercapacitors have been developed and commercialized. Among all, organic electrolyte-based L-ion batteries (LiB) account major portion of all the energy strage systems used in prtabel electronics, smart grids, and electric vehicles due to its high energy density, working potential window and power density. However, the poor rate capability due to limited ionic conductivity of organic electrolytes, high production cost, safety challenges arising from organic electrolyte and recyclability issues of Li-ion batteries hinders their application in future energy techonologies. On the other hand, aqueous ESS including aqueous metal ion batteries and aqueous super capacitors (AqSC) are gaining importance as alternatives to LiB's due to their improved safety, minimal maintenance, and production costs. Moreover, the aquesous electrolytes offer higher ionice conductivity than organic electrolytes ensure fast charge-discharge and high coulombic efficiency. Unlike LiBs, the solvents and salts used are cheaper and more environmentally friendly and do not have strict manufacturing conditions which reduces production cost. Although aqueous ESS have added advantage over LiBs, they are still far behind commercializaion due to their lower operationg voltage and poor cycling performance. The working potential window of aqueous ESS was limited due to electrolysis of water at 1.23 V. To enhance the working potential of Aqueous electrolyte many methods have been proposed such as chaning pH, introducing redox mediators, and constructing water in slat electrolyte. Although, aforementioned methods improve the potential window of aqueous electrolyte, the overall cell voltages of aqueous ESS is still far behind (2V) than LiBs due to low HER (Hydrogen Evolution reaction) and OER (Oxygen Evolution Reaction) overpotentials of electrode materials. For this reason, immense importance has given for the development of high OER/HER overpotentials and high-performance electrode materials for construction of advanced aqueous EES devices. Recently, Metal organic frame works (MOFs) has been immense importance as electrode materials for aqueous EES devices due to their porosity, low density, high specific surface area, tunable morphology and can function as both anodic and cathodic electrode materials. MOFs can be customized by choosing specific metal sites and tailoring their physical properties to achieve high power density and high energy densigy. Although these materials have been widely studied for aqueous EES, they are still far behind for commercialization due to their low conductivity, low HER and OER overpotentials, chemical instability in aqueous solutions and thermal instability. Although efforts are made to overcome these issues by insitu fabrication of binder free electrodes and hybridizing MOFs with carbonaceous materials, the working potential window of MOF based aqueous EES are still below 2 V. Therefore, rational design of MOFs with suitable aqueous electrolytes with high performance and large working potential window is of great significance for construction of next generation aqueous EEs. Hence the present proposal is aimed to develop MOF electrode materials in conjunction with suitable aqueous electrolytes for realization for high voltage aqueous ESS with good cycling stability.