Photocatalytic and/ or catalytic applications of Graphitic carbon nitride and hydroxyapatite-based nanomaterials for environmental remediation and energy storage and harvesting. Nanoscience and Nanotechnology, Nanocatalysts, Synthesis and characterization and application of inorganic nanostructured materials as catalysts, sorbents or polymer reinforcing nano-additives. Application of nanomaterials in various organic transformations, photodegradation of industrially emerging pollutants, bio-energy production and water treatment, waste-derived catalysts for various organic transformations and photodegradation of organic compounds, Waste plastics recycling, Coprocessing of petroleum vacuum residue, Polymers, Desulfurization, Solid Waste Management, Multifunctional Porous Materials (Metal-Organic Frameworks and Covalent Organic Frameworks) for Energy, Environment and Catalysis applications, Physical Chemistry. Organic synthesis, Synthesis of Schiff bases and Metal complexes, DFT, and Biological studies. Organic Chemistry and Renewable Energy. Studying the photophysical and photochemical processes of organic fluorophores in homogeneous and heterogeneous environments using fluorescence spectroscopy; protein-ligand interaction Transition metal complexes of nitrogen-based heterocyclic ligands: Synthesis, properties, and application. Organic Chemistry (Nano-structured materials for photocatalysis and medical/ bio-medical applications, etc.); Environmental Waste Management (Applications of Nano-materials derived from solid waste in Nano-electronics, Sensors, Nanocomposite fillers, etc.); Renewable (Biofuels) and Non-Renewable energy (Coal, Petroleum). Computational investigation of structure, bonding, aromaticity, and reaction mechanism. Electrocatalytic water oxidation and hydrogen evolution.