Synthesis of nano-gypsum: A computational approach to encounter soil salinity and land degradation

[Display omitted] •Computational and experimental investigation on Nano-Gypsum (NG).•Calculated minimum cluster energy is observed at ∼70 to 75 unit of gypsum.•NG causes reduction in soil pH, electrical conductivity and sodium adsorption ratio.•Deployment of NG helps to reclaim salt affected soil. Synthesis of nano-gypsum is one of emerging research area owing to its potential advantage to overcome the issue of soil salinity. Despite this interest, a little literature is available on its structural stability in nano scale length of gypsum. Thus, in this study a computational approach along with experimental investigation is used to investigate the effect of nano-gypsum on soil salinity. Density functional theory (DFT) is used to calculate energy of nano-gypsum clusters using hybrid functional field method (i.e. B3LYP). It is observed that evaluated binding energy, formation energy and vibrational spectra establishes the structural stability of CaSO4·2H2O cluster at ∼ 70 to 75 units of gypsum. The size of stable of nano-gypsum cluster and size of physically prepared nano-gypsum is close to each other. Further, deployment of nano-gypsum yields significant reduction in soil pH, electrical conductivity and sodium adsorption ratio during field trails indicating improved soil health.