Browsing by Author "Sujoy Sarkar"

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Efficacy of Methylammonium Iodobismuthate: A Green Catalyst for Reduction of Nitrate to Ammonia
(American Chemical Society, 2025) Vivek Kumar Agrahari; Abhik Bhuin; Ankur Yadav; Sujoy Sarkar; Subha Sadhu; Daya Shankar Pandey
Ammonia (NH3) is vital in agriculture and industry, yet its large-scale production remains energy-intensive and environmentally hostile. Herein, for the first time we report the development of lead-free nontoxic hexagonal methylammonium iodobismuthate metal halide perovskite (MABI) as a highly efficient and sustainable electrocatalyst for green ammonia production from nitrate reduction. The unique structure of MABI, featuring an isolated BiI6octahedron stabilized by a methylammonium cation, offers a highly tunable electronic environment required for nitrogen activation and hydrogenation. The experimental and computational studies categorically established the formation of an interconnected pure hexagonal structure with a band gap of ∼2.1 eV. Electrocatalytic nitrate reduction revealed that MABI displays a remarkable ammonia yield (27.53 μg mg–1h–1) with excellent stability and a quite impressive Faradaic efficiency (40%). This work highlights the potential of halide bismuthate perovskites as an alternative to traditional catalysts to produce ammonia in ambient conditions that address the dual challenges of energy efficiency and environmental sustainability. © 2025 American Chemical Society
Fabrication of a solution-processed low voltage TFT by using colloid 2D ZnO nanosheets and its application as a UV photodetector
(Royal Society of Chemistry, 2025) Abhik Bhuin; Akhilesh Kumar Yadav; Utkarsh S. Pandey; Debdyuti Mukherjee; Vivek Kumar Agrahari; Caroline Ponraj; Subha Sadhu; Bhola Nath Pal; Sujoy Sarkar
ZnO nanostructures have been extensively employed in optoelectronic devices because of their unique optoelectronic properties; however, these devices have been developed using physical vapor deposition techniques, which are costly and need a state-of-the-art fabrication facility. Hence, a solution-processed, cost-effective, low-temperature method is required for the large-scale fabrication of 2D material-based electronic devices. In this contribution, we report template, polymer, and surfactant-free wet chemical synthesis of 2D ZnO nanostructures having dimensions of ∼200 nm and thickness of ∼30 nm following the hydrothermal method. Detailed structural, morphological, and optical investigation revealed the formation of a pure hexagonal wurtzite phase of ZnO nanosheets. Utilizing the as-synthesized nanosheets, solution-processed thin film transistors (TFTs) are fabricated under low annealing temperatures that exhibit a high carrier mobility of 8.05 cm2 V−1 s−1 and an on-off ratio of ∼105. Also, these TFTs show high photosensitivity and can be used as UV detectors. Thus, our study highlights low-temperature facile fabrication of 2D ZnO TFTs, which may have promising applications in electronic displays, logic circuits, UV detectors, biosensors, and portable electronics. © 2025 The Royal Society of Chemistry.
Sequential submergence and drought induce yield loss in rice by affecting redox homeostasis and source-to-sink sugar transport
(Elsevier B.V., 2024) Santosh Kumar; Sahana Basu; A.K. Choudhary; Shashi Shekhar; J.S. Mishra; Sanjeev Kumar; Kumari Shubha; Rachana Dubey; Surajit Mondal; S.K. Dwivedi; N. Bhakta; Rakesh Kumar; Sujoy Sarkar; Srustidhar Dhamudia; Sunny Kumari; Anup Das; Arvind Kumar; Gautam Kumar
Rice cultivation in the rainfed ecosystems of the eastern Indo-Gangetic plain (EIGP) frequently comes across abrupt alternation of submergence and drought during the vegetative and reproductive stages, respectively, within one growing season, and this may be exaggerated with climate change. Therefore, development of combined submergence and drought tolerant rice genotypes might be a timely effort to meet the growing food demand. However, till date no study has been executed on the combination of submergence and drought stress in the field conditions of the EIGP. The present study elucidated the performance of near isogenic lines (NILs) of rice developed for the EIGP through marker assisted pyramiding of quantitative trait loci (QTL) associated with submergence (Sub1) and drought (qDTY1.1 + qDTY2.1 + qDTY3.1) in the background of the popular, high yielding Indo-Gangetic rice variety Swarna. This study included the screening of sixteen rice NILs along with the check varieties Swarna and Swarna Sub1 under cumulative submergence and drought for four consecutive rice growing years (2019–2022). Individual submergence or drought or cumulative stress caused 76, 47, and 85% respective loss in average productivity compared to that of the control conditions. However, rice NILs IR96321–558–563-B-2–1–1, IR96321–315–323-B-3–1–3, IR96321–315–294-B-1–1–1–1, and IR96321–558–209-B-6–1–1 showed outstanding cumulative stress tolerance with sustainable photosynthetic performance and membrane stability. Furthermore, these rice NILs exhibited effective reactive oxygen species scavenging mediated by enhanced antioxidant enzyme activities in source (flag-leaf) and sink (anther) tissues that contributed to conserving the source-to-sink mobilization, leading to improved pollen viability and spikelet fertility under sequential stress conditions. The study identified combined submergence-drought tolerant rice NILs along with an optimum yield level to support global food security and also represented a model crop system to establish mechanisms of multi-stress tolerance in plants. © 2024 Elsevier B.V.