Three new metal organic frameworks (ZnTIA-1mc, CuTIA-1mc, and CoTIA-1mc) were synthesized by the mechanochemical grinding (mc) method in the unadulterated form. They compared with their solvothermally synthesized (st) counterparts, where the mixtures of isomeric forms have been isolated. Kinetics study with the function of grinding time during the mechanosynthesis process revealed the formation of new metastable phases. Less crystallinity and short of mechanical defects in the structure of synthesized mc metal organic frameworks showed enhanced electrocatalytic activity toward oxygen evolution reaction (OER). Among all, CoTIA-1mc showed high OER activity with 289 mV overpotential, 10 mA cm–2 current density, and 55.4 mV dec–1 Tafel slope in 1 M KOH which is close to the commercially used RuO2.

Proton conducting materials have been gaining significant attention due to their applicability as solid electrolytes in proton exchange membrane fuel cells (PEMFCs). The confined architectural design and open space in...

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The present study has been executed to assess the groundwater quality and to investigate the possible sources of contamination in the adjoining areas of Ghazipur landfill site, Delhi. The groundwater samples were collected during pre and post monsoon seasons and various physico-chemical and heavy metals concentration were also analyzed. The results show that the samples which were taken adjacent to landfill site had a higher concentration of total dissolved solids (2383 mg/l), chloride (991mg/1), total hardness (659 mg/l), ammonical nitrogen (2.3mg/l), sodium (350 mg/l), calcium (534 mg/l) and sulphate (631 mg/l). Most of the heavy metals concentration in groundwater samples was found within the prescribed limit except Cu and Pb. The principal component analysis (PCA) extracted 3 factors which collectively explained 80.1% of the variation in data during post-monsoon whereas 75.4% of the variation in pre-monsoon season. The obtained results clearly show that K+, Mg2+, Na+, SO42-, and NO3- ions significantly contribute towards the high temporal pollution load to groundwater quality. Factor analysis also suggested that the continuous percolation of these contaminants from the nearby landfill could be the possible sources of contamination into groundwater aquifer system. The concentration of heavy metals in leachate have followed the order as- Fe>Zn>Cu>Pb>Ni>Cr>Cd. The overall result indicates that the landfill leachate is significantly affecting the nearby groundwater quality through continuous leaching over a long period of time. As the groundwater is used by some local residents for domestic purposes, immediate action and alternative effort should be made to supply clean water.

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