http://dspace.dtu.ac.in:8080/jspui/handle/repository/19775 Applied Chemistry Department 2026-07-03T16:07:32Z http://dspace.dtu.ac.in:8080/jspui/handle/repository/22964 Title: SYNTHESIS AND CHARACTERIZATION OF METALLOCORROLES AND IT’S APPLICATION Authors: KUSHWAHA, ANKIT; PATEL, ANKUSH; Kumar, Anil (SUPERVISOR) Abstract: Corroles are a group of tetrapyrrolic macrocycles that have drawn a lot of interest from researchers be cause of their special structural, electronic, and coordination properties. They are closely connected to porphyrins, but with one key difference — they are missing one meso-carbon atom. This makes their macrocyclic cavity smaller and gives them a trianionic ligand character. Because of these features, corroles can hold metals in uncommon oxidation states, which makes them useful in many scientific and technological areas. This dissertation covers the synthesis of corroles, their structural features, metallation reactions, methods of functionalization, and growing applications. A major focus is placed on developing efficient synthetic routes, which have made it much easier to prepare meso-substituted corroles. The work also discusses key reaction intermediates, the mechanisms behind macrocycle formation, and the factors that affect how well the synthesis works. The study also looks at how corroles coordinate with different metal ions, such as transition metals, lanthanides, and heavy metals. When a metal is inserted into the corrole ring, it changes the electronic and photophysical behaviour of the compound, leading to complexes with better catalytic and functional properties. 2026-06-01T00:00:00Z http://dspace.dtu.ac.in:8080/jspui/handle/repository/22963 Title: ARTIFICIAL NEURAL NETWORK-BASED MODELING OF LIQUID MEMBRANES FOR SEPARATION OF CERIUM (III) Authors: UROOJ, FATIMA; Jain, Manish (SUPERVISOR) Abstract: The rare earth elements (REEs) have been used in a range of applications from permanent magnets to catalysts, optical devices, electronic materials and many others, with remarkable quantities. The rare earth metal cerium (Ce) is widely used, however, because it is easily accessible in the industry. One of the methods which is promising to replace the conventional methods for separation and recovery of cerium from dilute aqueous solution is Emulsion Liquid Membrane (ELM) due to its high selectivity, low consumption of solvent, extraction-stripping process and high mass transfer efficiency. The process of extraction of Ce (III) ions was predicted and investigated in the present work by ANN modeling technique with ELM as carrier extractant, Span 80 as surfactant, Kerosene as diluent and HNO3 as stripping agent. The extraction time, pH of feed phase, concentration of the feed, and the concentration of the surfactant, stripping phase, stirring speed, phase ratio, treatment ratio and initial cerium concentration were used as input variables in this analysis. Feed forward multi-layer perceptron (ANN) was used to describe the effect of the process parameter to the extraction performance and the Levenberg-Marquardt back propagation algorithm was used for the training of the ANN. Five statistical measures MSE, Pearson correlation coefficient (R), RMSE, MAE and RPE were used to assess the model's predictive ability. The optimized 9–11–1 ANN model achieved overall R = 0.99082 (R² = 0.9817) and MSE = 26.145 (RMSE ≈ 5.11%). The sensitivity analysis shows that the biggest sensitivity is with the pH (28%) and the concentration of D2EHPA (23%). The obtained values obtained from the modelling were in good agreement with the experimental ones and the extraction behavior of Ce (III) was very accurate. This indicates that the modeling based on ANN is well suitable for the modeling of ELM for rare earth elements recovery. 2026-06-01T00:00:00Z http://dspace.dtu.ac.in:8080/jspui/handle/repository/22962 Title: ALKALI-MODIFIED KALANCHOE PINNATA LEAVES AS A BIOSORBENT FOR SEQUESTRATION OF CRYSTAL VIOLET DYE Authors: PAPOLA, UMA; KUMAR, ANIL (SUPERVISOR) Abstract: Nowadays, biosorbents derived from various plant parts have been explored for their ability to adsorb dyes, such as Crystal Violet (CV). It is observed that from a neutral to an alkaline medium, bio-materials-based biosorbents reveal a strong affinity towards cationic CV. The physicochemical properties, including equilibrium time, dye concentration, pH, and biosorbent dosage, have been investigated to determine the removal of CV from wastewater. The Leaf powder of Kalanchoe Pinnata (KP) has been found very efficient at 0.1 g/100 ml at alkaline pH. The adsorptive removal of CV was found to be 95% using activated KP. An isotherm study suggested that the process follows the Langmuir model, indicating that monolayer biosorption is occurring. The reusability of the developed activated KP was checked up to 4 cycles, and the results from real wastewater samples revealed that it can be used in real-time applications. 2026-06-01T00:00:00Z http://dspace.dtu.ac.in:8080/jspui/handle/repository/22957 Title: RECENT ADVANCEMENTS IN ELECTROCATALYTIC CO₂ REDUCTION USING DIFFERENT PORPHYRINOIDS Authors: AGGARWAL, HARSHITA; KUMAR, ANIL (SUPERVISOR) Abstract: The sharp, sustained rise in the concentration of carbon dioxide (CO₂) in the atmosphere, predominantly as a result of fossil fuel combustion, industrialization, deforestation and increased agricultural production, is one of the most pressing environmental challenges of the twenty-first century. The levels of atmospheric CO₂ have recently reached over 420 parts per million (ppm) compared to pre-industrial levels of around 280 ppm. This dramatic increase is the main contributor to anthropogenic climate change, causing global warming, sea level rise, ocean acidification and many natural ecosystems around the globe being affected. The electrocatalytic CO₂ reduction reaction (CO₂RR) is one of the various methods being investigated to tackle the issues of CO₂ accumulation. CO₂RR not only reduces CO₂ emissions but also generates valuable chemical feedstocks and fuels such as carbon monoxide (CO), formic acid (HCOOH), formaldehyde (HCHO), methanol (CH₃OH), methane (CH₄), ethylene (C₂H₄), and ethanol (C₂H₅OH), all of which can be used in various commercial applications instead of fossil fuels. If powered by electricity from renewable energies like solar, wind or hydro, CO₂RR is a carbon-neutral or even carbon-negative process. Porphyrinoids are a structurally very diverse and wide-spread group of macrocycles that has sparked special research interest due to its potential as catalytic materials in the reaction of CO₂RR. The porphyrinoids include porphyrins, metalloporphyrins, phthalocyanines, metallophthalocyanines, corroles, chlorins, bacteriochlorins and many derivatives. They have an important common structure feature: a highly conjugated macrocyclic aromatic structure with a central cavity to coordinate transition metal ions, giving well-defined and highly tunable metal coordination sites that act as the active centers for catalysis. The unique features of porphyrinoid-based electrocatalysts are their highly tuneable electronic structure, ease of synthetic modification at peripheral positions, excellent light-harvesting properties, precise single-atom metal centres as a basis for detailed mechanistic studies, and high selectivity for certain CO₂ reduction products. A number of recent studies have shown that these materials can be very efficient, have low overpotentials and are very stable for catalytic activity, providing significant promise for their use on a large scale. This dissertation provides a thorough overview of the recent developments on electrocatalytic CO₂ reduction with various porphyrinoid catalyst structures. The review systematically covers the basic principles of CO₂ chemistry and electrochemistry, structural and electronic properties of porphyrinoids, mechanisms of CO₂RR at porphyrinoid metal centres, performance of specific subclasses of porphyrinoids (porphyrins, phthalocyanines, corroles, and chlorins), effects of structural modification and the identity of the metal centre, immobilization strategies for the fabrication of electrodes, and challenges and future directions in this rapidly evolving field. The results presented in this work show that the iron and cobalt porphyrins have very high selectivity for CO production (Faradaic efficiencies > 95% at relatively low overpotentials). Cobalt phthalocyanines have been proven to be very active when immobilized on carbon supports, which catalyse the conversion of CO₂ to CO. Inspired by recent progress in corrole chemistry, a high CO selectivity with minimum competing hydrogen evolution can be realized. It has been demonstrated that the catalytic activity can be significantly improved by axial ligand modifications, peripheral functionalization and surface immobilization. The addition of porphyrinoids to metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) is an intriguing area that has produced highly active and robust catalysts. in The goal of this dissertation is to deliver a well-rounded and current overview of the state-of-the art porphyrinoid-based CO₂RR catalysis for graduate students, researchers, and electrocatalysis and materials practitioners, with an emphasis on the knowledge gaps and potential research directions for the field. 2026-06-01T00:00:00Z