Research News
- Dr Saleti Sumalatha published two patents in a row September 16, 2022
The Department of Computer Science and Engineering is glad to announce that Assistant Professor Dr Saleti Sumalatha and her students got two of their patent applications published in a row. The patent titled “System and method for mining of constraint based high utility time interval sequential patterns” (Application number: 202241044001) was published in collaboration with the BTech students; K Rasagna, N Naga Sahithya, K Hemalatha, B Sai Charan, and Upendra Karthik.
The main intention of the proposed system is to discover the sequences that include the time period between the purchases of each item. For example, if we consider a shop which sells some groceries like Grains, Milk, Yogurt, Bread and Eggs as the set of items in the database. Now, the main aim is to find the time period between the purchases of particular items that are being sold. From this, the shop owner can easily maintain the stock of completed items according to the time period.
For example, an output sequential pattern including time intervals of the form indicates that a customer who purchased item x also bought item y after three months and visited the store again after five months to buy item z. It considers the same utility threshold for each of the items in the database, which shows that each item is assumed to have the same unit profit. This is not convincing as each item is different in real-time applications and should not be treated equally. For example, the sales of” Gold bangles” will produce more profit than the sales of” Cotton Jeans”. In view of this, the research proposes UIPrefixSpan-MMU.
The other patent titled “A system and a method for automatic essay grading” (Application number: 202241043045) was published in collaboration with M Purnima, G Haveela, K U Meghana, and S Deepthi Reddy. Essay grading systems are being adopted by different organisations to reduce the hectic workload from a teacher’s point of view. They made a model which is trained with datasets containing different essay topics and numerous essays with scores varying in a wide range.
Essay grading systems will not only save the time for evaluation but also give accurate results. The output of the system will be quick such that it could evaluate many essays and get trained. This system benefits both the student and the teacher as well. Their model predicts the scores of the essay by comparing them with the features extracted from the trained data. This model can be used to reduce the effort of teachers to grade many essays in a limited time. The work of grading will be fastened and accurate.
Continue reading → - Effective combinatorial drug therapy for prostate cancer September 13, 2022
Prostate cancer is the second most frequent solid organ malignancy in males worldwide. The risk of causing prostate cancer is increased by age, race, and family history. The U.S. FDA has approved the six most successful drugs, viz., docetaxel, sipuleucel-T, abiraterone, enzalutamide, cabazitaxel, and radium-223. Despite these approved therapies, the disease state remains lethal. The recent publication of Dr Imran Uddin, Post Doctoral Fellow, Department of Physics, “Targeted non-AR mediated smart delivery of abiraterone to the prostate cancer” proposes a combinatorial system against prostate cancer using the FDA-approved drug abiraterone. The paper was published in the Q1journal PLoS ONE having an Impact Factor of 3.75. The research was done in collaboration with Dr Mohd Sajid Khan, Associate Professor, Aligarh Muslim University.
Although abiraterone is an excellent anticancer agent, it causes several side effects and becomes irresponsive after a few months of therapy. They developed a nanomedicine, along with two other components, that will deliver a substantially small dose of abiraterone for treating the same stage of cancer, and the drug will also not be resistant to the cancer cells. The delivery system delivered the drug at a specific site and modified its mode of action. The low dose of abiraterone will also not cause any substantial side effects. The combo was found to be highly biocompatible, nontoxic, and effective.
The proposed nanomedicine with established drug abiraterone, gold nanoparticles, and antibodies against cancer-promoting protein synergistically acted on prostate cancer cells. This synergism potentiated the effect of abiraterone at a very low concentration because other entities also acted via different routes and weakened the cancer cells. The low dose minimized the side effects and maintained patient compliance. This drug was delivered directly to the target, which enabled it to adopt different methods to act on cancer cells. Therefore, the results were promising but further needed to be validated in pre-clinical and clinical studies.
In future, Dr Uddin intends to focus on interdisciplinary sciences. His plans include studying the interface of biology with inorganic nanomaterials, understanding the underlying biological process, and developing new industrially relevant nanomaterials and biomedical aspects. It involves developing nano biosensors for biomolecule detection through the effective integration of the best approaches and expertise in sensor engineering with the vision to take a lead in shaping the future of biomedical monitoring systems. The timely integration of such interdisciplinary approaches will consolidate the application of Lab-on-a-Chip devices for automated biomolecular monitoring.
Abstract of the Research
Prostate cancer is the second-deadliest tumour in men all over the world. Different types of drugs with various delivery systems and pathways were developed, but no one showed prominent results against cancer. Meanwhile, nanotechnology has shown good results against cancer. Therefore, in the given study, citrate mediated synthesized gold nanoparticles (CtGNPs) with immobilized survivin antibodies (SvGNPs) were bioconjugated to the substantially potent drug abiraterone (AbSvGNPs) to develop as a combinatorial therapeutic against prostate cancer. The selected drug abiraterone possesses exceptionally good activity against prostate cancer, but cancer cells develop resistance against this drug and it also poses several severe side effects. Meanwhile, survivin antibodies were used to deliver AbSvGNPs specifically into cancer cells by considering survivin, an anti-apoptotic overexpressed protein in cancer cells, as a marker. The surviving antibodies have also been used to inhibit cancer cells as an immunotherapeutic agent. Similarly, CtGNPs were discovered to inhibit cancer cell proliferation via several transduction pathways. The given bioconjugated nanoparticles (AbSvGNPs) were found to be substantially effective against prostate cancer cells.
Continue reading → - Security concerns in digital image transmission over the internet September 13, 2022
The research team from the Department of Computer Science and Engineering proposes a research scheme to address security concerns in the transmission of digital images of aerial Remote sensing images over the Internet. Assistant Professor Dr Priyanka, Assistant Professor Dr Jatindra Kumar Dash, research scholar Ms K Jyothsna Devi, and BTech student Mr. M V Jayanth Krishna, published the paper A New Robust and Secure 3-Level Digital Image Watermarking Based on G-BAT Hybrid Optimization in the Mathematics Journal SCI, a Q1 Journal with an Impact Factor of 2.9. The research project combats various threats in the transmission of Remote sensing images, such as copyright protection, copy control, and unauthorized access.
Abstract
This contribution applies tools from the information theory and soft computing (SC) paradigms to the embedding and extraction of watermarks in aerial remote sensing (RS) images to protect copyright. By the time 5G came along, Internet usage had already grown exponentially. Regarding copyright protection, the most important responsibility of the digital image watermarking (DIW) approach is to provide authentication and security for digital content. The main goal of the paper is to provide authentication and security to aerial RS images transmitted over the Internet by the proposal of a hybrid approach using both the redundant discrete wavelet transform (RDWT) and the singular value decomposition (SVD) schemes for DIW. Specifically, SC is adopted in this work for the numerical optimisation of critical parameters. Moreover, 1-level RDWT and SVD are applied to digital cover images and singular matrices of LH and HL sub-bands are selected for watermark embedding. Further selected singular matrices S LH and S HL are split into 3 × 3 non-overlapping blocks, and diagonal positions are used for watermark embedding. Three-level symmetric encryption with a low computational cost is used to ensure higher watermark security. A hybrid grasshopper–BAT (G- BAT) SC-based optimization algorithm is also proposed to achieve high-quality DIW outcomes, and a broad comparison against other methods in the state-of-the-art is provided. The experimental results have demonstrated that the proposal provides high levels of imperceptibility, robustness, embedding capacity, and security when dealing with DIW of aerial RS images, even higher than the state-of-the-art methods.
The proposed scheme is easily dumped into the sender and receiver machines to work readily. MATLAB platform is the only requirement. Researchers aspire to design new image watermarking schemes using machine learning and deep learning techniques. For this project, they have collaborated with Professor José Santamaría from the Department of Computer Science, University of Jaén, and Professor Antonio Romero-Manchado from the Department of Cartographic Engineering, Geodesy, and Photogrammetry, University of Jaén.
Continue reading → - Defect detection algorithms September 9, 2022
Research at the Department of Electronics and Communication Engineering is currently developing defect detection algorithms. Assistant Professor Dr V Udaya Sankar, Professor Dr Yellampalli Siva Sankar, and their BTech student Ms Gayathri Lakshmi have published a paper, A Review of various defects in PCB, in the Journal of Electronic Testing: Theory and Applications with an impact factor of 0.795.
Abstract
Printed Circuit Boards (PCBs) are the building blocks for all electronic products. Fabrication of a PCB involves various mechanical and chemical processes. As obtaining accuracy in the mechanical and chemical processes is very difficult, various defects/faults are formed during PCBs fabrication. These fabrication defects lead to performance degradation of electronic products. This paper describes multiple defects present in PCBs under the Through-hole and SMD categories. To understand the frequency of occurrence and reason for defects in both manual and machine, PCB fabrication data was collected and analysed from April 2017 to July 2020 as a part of industry collaboration.
The research is a review done on the defects present in PCB. Researchers surveyed various papers on PCB defects and their detection. Based on the literature review and information obtained from Efftronics systems Pvt. Ltd, they classified the defects, gave a detailed explanation for each, and provided some analysis of their occurrences.
While doing the literature review, researchers observed that no paper mentioned all the defects that can occur in the case of PCB fabrication. For this reason, they came up with this paper which provides detailed information regarding the defects. Information is also obtained from the industry. Comparing the defects can help focus on the critical defects for future research on defect detection methodology.
The project is done in collaboration with Efftronics Systems Pvt. Ltd. Through the partnership, the company supported sharing images, insights information related to defects and involved in discussions. Also, the company allowed visiting their premises to understand more about PCB defects. Researchers look forward to creating a prototype that detects all the defects mentioned in this paper for a given PCB.
Continue reading → - Studying the critical behaviour in physical systems through inequality analysis September 9, 2022
Dr Soumyajyoti Biswas, Assistant Professor from the Department of Physics, has been keenly involved in intense research around areas like the statistical physics of fracture and breakdown in disordered materials and machine learning methods in predicting the imminent breakdown in disordered systems. He has recently published two articles titled “Success of social inequality measures in predicting critical or failure points in some models of physical systems” and “Evolutionary Dynamics of Social Inequality and Coincidence of Gini and Kolkata indices under Unrestricted Competition” in the journals Frontiers in Physics and International Journal of Modern Physics C respectively. The research was done in collaboration with various academicians and undergraduate students (BTech CSE and BSc Physics) from the Indian Statistical Institute, Kolkata and Saha Institute of Nuclear Physics, Kolkata.
It is known that physical systems behave erratically near critical points. Since the 1970s, the ‘erratic’ behaviour has been explained in terms of critical phenomena, and it was found that there are some robust patterns in classes of systems, e.g., all liquid-gas transitions have something in common. Those common patterns were quantified in terms of critical exponents – some numbers that belong to a particular class of systems.
The research shows that if the ‘erratic’ responses of systems near critical points are quantified by some measures of inequality indices (higher the values of the indices, higher the inequality), then such indices behave in a near-universal way for different physical systems, even if they belong in different universality classes. The articles have shown such behaviour in models of physical systems. They have also shown that in socio-economic data, which are also the systems that were conjectured to be in the self-organized critical state. The behaviour from real data matches very well with those from the model simulations.
The researchers have tested their observations from the model simulations to various socio-economic systems that were long conjectured to be in the state of self-organized criticality. Specifically, they have looked into the income inequalities in the US, inequality in citations of authors, inequality in income from movies, and inequality in fluctuations of Bitcoin markets. In all these systems, the participating agents compete among themselves without much external intervention.
In fact, the only system among these where there are some interventions is income inequality. They have shown that through data from the IRS in the US, that inequality has consistently grown in the 1980s till date and has been following the path predicted in our model simulations.
In future, they plan on continuing along this line of looking at critical behaviour in physical systems through inequality analysis. Particularly for the systems where the critical point can represent a catastrophic event (say, fracture) and it is important to quantify the distance from such a catastrophic point.
Abstract of the Research
In many physical systems, experimentally measurable quantities vary drastically near the critical point of such systems. For example, in liquids turning into gas, the densities fluctuate, similar fluctuations happen for magnetisation near critical temperature. We have shown that in systems where the critical point is self-organized i.e., the system reaches the critical point on its own, the unequal nature of their responses show nearly universal trends, even if the models belong to different universality class. This observation could then be used in physical and also socio-economic systems, to quantify their distance from critical point.
The right hand side figure illustrates the variation of the inequality indices and the circle indicates the critical point where the system is evolving towards. On the left hand side, the picture presents the same indices for income inequality in the US. It has been observed that the inequality has grown over the years and tending towards the saturation value (about 0.86) in a very similar way that is seen in models.
Continue reading → - Studying the agricultural transformation in Southeast Asia September 8, 2022
The promotion of sustainable growth of agriculture is one of the primary concerns of developing nations. The agriculture domain in Southeast Asia has undergone rapid transformation and structural changes over the last few years. Assistant Professor Dr Ghanshyam Pandey from the Department of Economics discusses the reasons for this changed scenario in his latest publication “Transformation and Sources of Growth in Southeast Asian Agriculture”. The research conducted in collaboration with International Food Policy Research (IFPRI) and the Indian Council of Agricultural Research (ICAR) was published in the Q2 journal Southeast Asian Agriculture having an Impact Factor of 1.7.
Abstract of the Research
Over the past few decades, agriculture in Southeast Asia has experienced robust growth and undergone a significant structural transformation, albeit at a different pace in different countries in the region. This paper aims to understand the agricultural transformation and growth process in Southeast Asia. The findings of this study show that driven by technological change, area expansion, and diversification, agriculture has grown faster in low-income countries in the region. In contrast, agricultural growth in high-income countries has been slow and driven by price increases, mainly of export-oriented commercial crops such as oil palm, rubber, and coconut—alongside an expansion of cropped areas under these crops. In view of the fixed supply of land and high volatility in global food prices, the area- and price-driven growth is not sustainable in the long run. For efficient, sustainable, and inclusive growth, exploiting the potential of existing and frontier technologies and diversification of production portfolios holds greater promise.
- Modified solar air heater for preserving agricultural produce September 5, 2022
There is a growing demand for decentralised systems that use renewable energy to extend the shelf life of agricultural commodities. Solar Air Heating systems (SAHs) are effective and environmentally friendly systems used to preserve agricultural produce by lowering the moisture content. Assistant Professor Dr Karthik Rajendran and his Post-Doctoral Scholar Dr VS Vigneswaran from the Department of Environmental Science have published their paper “Augmented v-corrugated absorber plate using shot-blasting for solar air heater – Energy, Exergy, Economic, and Environmental (4E) analysis” in the Q1 journal “Process Safety and Environmental Protection” having an Impact Factor of 7.9. The paper was published in collaboration with D. Sung Chul Kim, Shandong University, China.
South Asia is home to the majority of the world’s hungry people. Among 116 nations, India, the second-most populated nation in the world, is ranked 101st in the global hunger index. There is cause for concern given that India loses over 67 million tonnes of food annually, which is equivalent to about Rs. 92,000 crore. In 2016, the Indian Council of Agricultural Research estimated that during harvest, post-harvest, processing, and storage, about 4.3-6.1% of pulses, 3.9-6% of grains, 2.8-10.1% of oilseeds, 6.9-13% of vegetables, and 5.8-18.1% of fruits were lost. 16% of fruits and vegetables as well as 10% of oilseeds, pulses, and cereals were lost in India due to inadequate access to storage facilities.
Each year, these losses increase in India. In order to reduce food wastage after harvest and the amount of people going hungry in India, technologies must be developed to extend the shelf life of agricultural produce. The utilisation of land, water, energy, and the release of greenhouse gases into the atmosphere can all be decreased by reducing postharvest loss. It is necessary to develop a decentralised system that uses renewable energy to extend the shelf life of agricultural products. Given that the majority of India has abundant solar energy resources, solar crop dryers based on solar air heaters (SAH) are a practical choice for conserving agricultural output by lowering its moisture content. These technologies are appealing because they are affordable and sustainable.
The performance of SAH is determined by the absorber plate. Thus, the SAH was modified with a v-corrugated absorber plate with a shot-blasted surface, and the SAH performance was investigated experimentally. Performance parameters including the energy and exergy efficiency of the collector were determined and compared with those of the conventional SAH. The study inferred that SAH optimisation will make way for the maximisation of its efficiency.
Abstract of the Research
Need for increasing the shelf life of agricultural produce using renewable energy-based A decentralized system are significantly increasing. The solar air heating systems (SAHs) are efficient and environment friendly systems which are used for preserving agricultural produce through the reduction of moisture content. However, these systems had poor thermal efficiency and the way for increasing the efficiency are much need in the present era. This article presents the energy, exergy, and economic analysis of a modified solar air heater system (SAH). The proposed (modified) SAH has a V-corrugation absorber plate; the inner surface was modified using shot-blasting technology. This is the first study to experimentally investigate a modified SAH and compare the results with those of a conventional SAH. Additionally, an environmental and sustainability assessment of the SAH is presented. The SAH performance was tested at airflow rates ranging from 0.01 to 0.02 kg. sec.
Continue reading → - Dr Pankaj Pathak co-edited and authored in the springer publication series September 5, 2022
Dr Pankaj Pathak, Assistant Professor, Department of Environmental Science co-edited the book “Circular Economy in Municipal Solid Waste Landfilling: Biomining & Leachate Treatment: Sustainable Solid Waste Management: Waste to Wealth” in collaboration with Prof Sankar Ganesh Palani from BITS Pilani, Hyderabad. The book was released as part of the Springer publication series ‘Radionuclides and Heavy Metals in the Environment’ that covers issues pertaining to environmental pollution of air, water and soil, causative toxic agents, including radioactive materials, and remediation strategies.
The book is a ready reckoner of contemporary information regarding municipal solid waste landfill biomining, treatment of landfill leachate and heavy metals in a single platform. Construction of new landfills which requires huge monetary investments can be avoided if old landfills were bio-mined for resources and the space can be re-used as new landfills. Landfill leachate is a hazardous waste which needs proper treatment that could generate value-added products such as clean energy and biofertilizers. The book is a rich repository of information for academicians, researchers, and students at master’s and doctoral levels to understand the current trends in municipal solid waste landfill operations.
It also features the chapter, ”Valorization of Solid Waste from Landfill Activities” co-authored by Dr Pankaj Pathak and her PhD scholar MSSR Tejaswini along with Prof Sankar Ganesh Palani and Dr Prangya Ranjan Rout from Thapar Institute of Engineering and Technology. The article states that urban mining of various types of landfill wastes helps in the conservation of natural resources as well as increases the economic value of the disposed of wastes. It also ensures maximum recovery from the wastes that can be used as a secondary raw material for production purposes. Accordingly, they determine the environmental impacts associated with landfill wastes and identify different technologies that would help in the conversion of waste into resources through urban mining.
Essentially the book provides a circular economy approach to municipal solid waste (MSW) management. It also reviews the current technologies and future trends in MSW treatment by focusing on technological solutions for MSW treatment in developing countries in comparison with developed countries.
Continue reading → - Large-scale production of BP nanosheets September 1, 2022
Research at the Department of Physics has effectively produced and characterised BP nanosheets on a large scale by a simple solvothermal approach, and the formation mechanisms are discussed. The paper, 2D-Black Phosphorus/Polyaniline Hybrids for Efficient Supercapacitor and Hydrogen Evolution Reaction Applications Check for updates, has been published by Prof Ranjit Thapa, Associate Dean of Sciences, as a corresponding author, and his PhD student, Mr Samadhan Kapse in Sustainable Energy & Fuels having an Impact Factor of 6.367.
Abstract
Black phosphorous (BP) is an emerging 2D material with exciting physicochemical properties with broad applicability in electronics. Stability in the ambient environment, large-scale synthesis, and volume expansion during the charge/discharge process hinder its application in energy storage. Here, we report a facile gram-scale synthesis of BP in a mild reaction condition by a simple and cost-effective wet chemical method. To overcome its degradation and sluggish electrochemical performance, an organic hybrid with polyaniline is also prepared. Further, we fabricated a flexible supercapacitor device which results in an exceptional specific capacitance of 969 mFcm-2 at a current density of 0.4 Acm-2, which displayed a high energy density of 21.5 mWhkg-1 at a power density of 231 mWkg-1 with good cycling stability of 91% after 4000 charge-discharge cycles. Similarly, the cyclic voltammetry studies of the flexible devices at various bending angles display a similar CV profile for all the bending angles, which confirms the device’s reliability for flexible applications.
Explanation of the research
BP-PANI hybrid materials were prepared by the in-situ chemical oxidation method. By this approach, the researchers got highly stable BP by an inorganic-organic linkage, and its energy storage performance was also investigated. The fabricated symmetric flexible supercapacitor device based on BP/PANI heterostructure exhibited an extraordinary specific capacitance of 969 mFcm-2 at a current density of 0.4 Acm-2. Moreover, the fabricated device showed a high energy density of 21.5 mWhkg-1 and a power density of 231 mWkg-1 with impressive cycle stability of 91% after 4000 charge-discharge cycles. This study paves the way for future research into gram-scale BP synthesis, stability via an inorganic-organic coupling, and its potential application in electrochemical energy storage devices.
Social implications of the research
With the rapid growth of portable/flexible electronics and the high demand for clean energy, supercapacitors have sparked interest due to their advantages of fast charge/discharge rates, long cycle life, and high-power density compared to conventional energy-storage devices such as dielectric capacitors and Li-ion batteries. Likewise, developing new functional materials with outstanding properties could shed light on many issues, including pollution, energy, synthesis, and cost. In recent years few graphene analogues materials have been explored, and because of their tuneable physicochemical properties, they were used in energy storage applications. Generally, black phosphorus was synthesised from polymorphs of phosphorus under vigorous reaction conditions. However, these high temperature/pressure conditions suffer from safety, toxicity, controllability, and gram-scale production.
Quantum capacitance is an efficient tool for rapidly screening materials for supercapacitor applications and therefore is the future of this research. The researchers have collaborated with Mr Namsheer K, Mr Mridula Manoj, Mr Aditya Sharma, and Dr Chandra Sekhar Rout from the Functional Materials & Devices Laboratory, Centre for Nano Material Sciences, Jain University, Bangalore, India, in this work.
Continue reading → - Efficient and selective single-atom catalysts for eNRR September 1, 2022
The Department of Physics is glad to announce that Dr Ranjit Thapa and his PhD scholar Mr Samadhan Kapse have published their research paper “Descriptors and graphical construction for in silico design of efficient and selective single-atom catalysts for eNRR” in the journal Chemical Science, having an Impact Factor of 9.969. The paper was published in collaboration with Prof Shobhana Narasimhan, Theoretical Sciences Unit and School of Advanced Materials, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore. Chemical Science is a highly prestigious nature Index journal, which accepts only breakthrough research contributions for publication.
The Haber-Bosch process for ammonia synthesis has been described as possibly the most important scientific discovery of the twentieth century. However, it requires high temperatures and pressures and results in large energy consumption and emission of greenhouse gases. That is where electrochemical nitrogen reduction reaction (eNRR) comes into the picture. It synthesizes ammonia from nitrogen and water under mild conditions (N2 + 6H+ + 6e- → 2NH3). However, currently available eNRR catalysts need improvement in three respects: (i) the efficiency of nitrogen fixation needs to be increased, (ii) the competing hydrogen evolution reaction (HER) needs to be suppressed, and (iii) hydrogen poisoning of active sites must be avoided. Transition metals are popular eNRR catalysts; however, they tend to favour hydrogen adsorption due to the formation of strong metal d – hydrogen σ bonds, and tend to have a low affinity for N2 adsorption. Their research mitigates these problems by appropriately tuning the electronic structure by altering the environment surrounding metal atoms at the active site of single-atom catalysts (SACs). Moreover, in previous works, typically, only one criterion (usually competing HER) was used to optimize catalyst function, whereas they simultaneously optimised the catalyst function with respect to multiple criteria.
They have screened 66 different transition metal-based SACs for possible use in eNRR. To determine the best possible catalyst, they considered three factors: N2 adsorption, hydrogen poisoning and the overpotential of eNRR. Here, the valence electron occupancy (Oval) is identified as a new electronic descriptor that can predict the overpotential value. They emphasised that having a low η_NRR alone does not suffice to indicate a suitable eNRR catalyst, since if the adsorption free energy is higher for H than N2, active sites will be poisoned, hindering eNRR. Thus, they present a simple graphical procedure for identifying the most promising catalysts. To carry out this procedure, one must compute only 〖ΔG〗_(H^* ) and 〖ΔG〗_(NNH^* ), the changes in the free energies of H and NNH adsorption, respectively (note that η_NRR can be deduced if 〖ΔG〗_(NNH^* ) is known). The most promising candidate is identified as Sc-Pc, which they predict will have no H poisoning and will be highly selective for eNRR over HER. Moreover, they predict that Mn-Pc, Cr-N4, Fe-N2C2 should also be highly efficient, with low overpotential (η_NRR < 1 V) toward eNRR, and no H poisoning. In future they aim to find the selective materials for catalytic reactions by studying the origin of activity, reaction mechanism, etc.
Abstract of the Research
The electrochemical nitrogen reduction reaction (eNRR) offers the possibility of ammonia synthesis under mild conditions; however, it suffers from low yields, a competing hydrogen evolution reaction pathway, and hydrogen poisoning. We present a systematic approach toward screening single atom catalysts (SACs) for eNRR, by focusing on key parameters computed from density functional theory, and relationships between them. We illustrate this by application to 66 model catalysts of the types, TM-Pc, TM-NXCY, and TM-N3, where TM is a 3d transition metal or molybdenum. We identified the best SACs as Sc-Pc, Cr-N4, Mn-Pc, and Fe-N2C2; these show eNRR selectivity over HER and no hydrogen poisoning. The catalysts are identified through multi-parameter optimization which includes the condition of hydrogen poisoning. We propose a new electronic descriptor Oval, the valence electron occupancy of the metal center, that exhibits a volcano-type relationship with eNRR overpotential. Our multi-parameter optimization approach can be mapped onto a simple graphical construction to find the best catalyst for eNRR over HER and hydrogen poisoning.