Browsing by Author "Girijesh Kumar"

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Abundance of trace and rare earth elements (Ree) in ferromanganese nodules of the central Indian ocean basin
(Books and Journals Private Ltd., 2021) Saurabh Kumar Barman; Sanjay Kumar Tiwari; Girijesh Kumar; Ishwar Chandra Rahi
Ferromanganese nodules of CIOB contains significant concentrations of Mn, Cu, Ni, Zn, Co and rare earth elements (REEs). To decide occurrence and enrichment processes of those metals in nodules, we carried out excessive-resolution mineralogical and geochemical research on Mn-nodules. Nodules display an excessive average abundance of Mn (avg. 25.63%), slight Fe (avg. 8.91%) and low contents of trace elements and REEs compared to moderate content of nodules from different oceanic areas. Some crucial metals of economic interest, notably Co, Cu, Ni, Mo, and Zn are lower in nodules of CIOB than in nodules from different oceans. They are rich in REEs, Fe, Mn, Cu, Co, Mo, Ni, Zn and other useful metals. Here, Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), an experimental technique with characteristics of correct principle, apparent interference, smooth operation, and reliable results have been used for bulk chemical analyses for trace and REEs of various size nodules. Twenty-nine elements viz. V, Cr, Mn, Co, Ni, Zn, Rb, Sr, Nb, Mo, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, Lu, Hf, Pb, Th and U were measured. The concentrations of these twenty-nine elements in nodules are strategic REEs resource and could be used for resource exploration, environmental assessment and will likely catalyze further advanced analysis investigation of seabed resources in CIOB. © 2021, Books and Journals Private Ltd.. All rights reserved.
Carbonaceous Catalysts for Pollutant Degradation
(wiley, 2023) Poonam Kaswan; Santimoy Khilari; Ankur Srivastava; Girijesh Kumar; Pratap K. Chhotaray; Mrituanjay D. Pandey; Kamalakanta Behera
To enhance the quality of the environment, a lot of studies have been done on carbonaceous materials to develop different architectures and qualities. The development and importance of carbonaceous photocatalysts is briefly highlighted in this chapter, which also includes different semiconductors based on activated carbon, carbon nanotubes, carbon dots, fullerene, graphene, aerogels and carbon sponges, etc. In the present chapter, we have considered two types of strategies to discuss the entitled topic, one is a carbon-based catalyst, and the second is carbonaceous material with other metal composites to enhance the activity. Various difficulties with a metal catalyst, such as limited light adsorption capacity, large band gap energy, and insufficient physicochemical stability, continue to severely restrict photocatalysts for practical uses. To get rid of this, some unique catalysts based on carbon materials have been designed and inserted into a photocatalytic system to enhance activity. They are found to be ideal for various types of applications ranging from the field of renewable energy to waste water management and treatment, thanks to the synergistic combination of metal nanoparticles and carbonaceous nanostructures. Carbon-based metal nanostructures are much essential to dissolve a variety of colorful and colorless hazardous contaminants, such as organic dye, NOXelimination, water splitting, etc., when they are subjected to visible light. © 2023 Scrivener Publishing LLC.