Research interest
Photoelectrochemical water splitting
Using sunlight and specialized semiconductor materials, photoelectrochemical water splitting (PEC) converts solar energy directly into chemical energy to split water molecules into hydrogen and oxygen.The semiconductors used in the PEC process are comparable to those used in photovoltaic solar electricity generation; however, in PEC applications, the semiconductor is submerged in a water-based electrolyte, where sunlight powers the water-splitting process. This is a long-term technological route with negligible or no greenhouse gas emissions.
Physico-chemical properties of morphologically tuned nanomaterials
A bulk material's physical characteristics are unaffected by its size, whereas a nanoparticle's physical and chemical characteristics depend on its size. Thus, when a material's size approaches nanoscale proportions and as the number of atoms at its surface increases, its properties alter. Depending on their morphological entities, their vibrational modes and optical absorption wavelength also differ leading to different bandgaps. All these characteristics alter the energy-related (catalytic) properties of the synthesized nanoscale materials.
I am very much interested in analyzing and understanding the synthesized samples through various primary characterization techniques - XRD, XPS, HRTEM, BET, FESEM, Raman, UV-vis spectroscopy, etc., which could be effectively used for various applications.
Hydrogen Evolution Reaction
The Hydrogen Evolution Reaction (HER) is a two-electron transfer reaction (cathodic reaction) where H2 gas is produced when protons or water are reduced at the electrode surface. Significant attention is paid to developing H2 through electrochemical water splitting to replace fossil-fuel-based technologies and drive the future toward zero-emission transportation. Enormous steps have been put forward by researchers to identify and utilize the most efficient and stable electrocatalyst (other than Platinum) for HER.
Here I'm interested in developing competent nanoscale electrocatalyst materials to understand the underlying mechanism of HER working in a broader pH spectrum and also on different types of substrates as an electrode base.
Oxygen Evolution Reaction
The Oxygen Evolution Reaction (OER), compared to HER requires four-electron transfer for the evolution of an oxygen molecule in the anodic counterpart. As a result, the reaction kinetics are mostly sluggish and need incorporating and calibrating high-end nanoscale electrocatalysts to deliver the optimum efficiency considering the cost factor. Presently, RuO2 and Ir-based electrocatalysts rule the OER part which has to be restricted to develop novel and high-performing OER electrocatalysts.
I have worked in incorporating different types of dopant metal ions to increase the electrochemical performance of metal oxides to deliver long endurance and highly efficient OER electrocatalysts in different pH media and substrates.
Supercapacitors
Storing energy through batteries and delivering excellent specific power through supercapacitors are both necessary to fill the space dedicated to energy storage systems. While batteries can provide ~10x more energy over much longer periods of time than a supercapacitor can (higher specific energy), supercapacitors can deliver energy ~10x quicker than a battery can ( higher specific power)
My research has been involved in investigating the pseudocapacitive and EDLC behavior of highly porous nanomaterials in different substrates to deliver high specific energy with exceptional cyclic stability and durability.
Nanomaterials and Magnetism
Magnetic nanoparticles are discovered to display fascinating and noticeably different magnetic properties than those observed in their comparable bulk materials. These differences can be attributed to finite-size effects, such as the high surface-to-volume ratio and distinct crystal structures.
During my initial research days, I was involved in understanding how the magnetic properties such as magnetic field intensity, susceptibility, coercivity, etc., could affect the different ferrite nano-morphologies.
Dielectric characteristics and complex Impedance parameters
Dielectric materials can be utilized for numerous applications, including enhancing the performance of capacitors, semiconductors, and other energy storage systems. The dielectric attributes can be probed by using real and imaginary components of permeability (ε' and ε''), loss tangent (tanδ), and ac-conductivity (σac). The dielectric behavior describes the nature of charge carriers and the conduction process generally influenced by factors such as cation distribution, synthesis technique, temperature, applied field, grain size, and composition of the material.
I was involved in measuring the resistances and capacitances of ferrite-based specimens by tuning the temperature and frequency of the pellet samples using an AC signal.
Photodegradation for dye removal
Heterogeneous catalysis is used for the degradation or bleaching of dyes. Reactive oxygen species and hydroxide radicals are produced when the generated excitons after light absorption interact with oxygen or water. These species have a powerful oxidizing ability and can break down many compounds, including synthetic dyes.
I was engaged in investigating different ferrite nanoparticles for the photodegradation of dyes for wastewater treatment.