Structure, reactivity, and magnetism: adsorption of NH3 around Nin

Fabrication of magnetic nickel incorporated carbon nanofibers for superfast adsorption of sulfadiazine: Performance and mechanisms exploration

Herein, novel magnetic nickel incorporated carbon nanofibers (Ni@CNF) were successfully synthesized via electrostatic spinning method for sulfadiazine (SDZ) adsorption. We combined computational and experimental tools to clarify the distinct nature of SDZ on Ni@CNF. Extensive computations and characterizations of SDZ-Ni adsorption complexes evidenced that Ni atoms were indispensable for SDZ adsorption and increasing the number of Ni atoms in Ni@CNF significantly improved SDZ adsorption due to the lower adsorption energy (E_ad). As we surmised, the adsorption capacity of Ni@CNF enhanced gradually with increasing the mass ratio of Ni in the composite. The as-prepared 9%Ni@CNF achieved removal efficiency of 98.9% for SDZ (2.5 mg/L) in 25 min, while the pure CNF hardly removed any SDZ under the identical conditions. The experimental data was better fitted by the Langmuir model with the maximum monolayer adsorption capacity of 103.21 mg/g at 318 K. Besides, the 9%Ni@CNF exhibited great applicability to various organic contaminants, and excellent stability and reusability over five consecutive cycles. Overall, for the first time, we provide the evidence that Ni atoms in the Ni@CNF plays a crucial role in SDZ adsorption, which can guide us for constructing nickle incorporated adsorbents with impressive adsorption capacity in environmental remediation.

Homonuclear transition-metal trimers

Density-functional theory has been used to determine the ground-state geometries and electronic states for homonuclear transition-metal trimers constrained to equilateral triangle geometries. This represents the first application of consistent theoretical methods to all of the ten 3d block transition-metal trimers, from scandium to zinc. A search of the potential surfaces yields the following electronic ground states and bond lengths: Sc3(2A1',2.83 A), Ti3(7E',2.32 A), V3(2E",2.06 A), Cr3(17E',2.92 A), Mn3(16A2',2.73 A), Fe3(11E",2.24 A), Co3(6E",2.18 A), Ni3(3A2",2.23 A), Cu3(2E',2.37 A), and Zn3(1A1',2.93 A). Vibrational frequencies, several low-lying electronic states, and trends in bond lengths and atomization energies are discussed. The predicted dissociation energies DeltaE(M3-->M2+M) are 49.4 kcal mol(-1)(Sc3), 64.3 kcal mol(-1)(Ti3), 60.7 kcal mol(-1)(V3), 11.5 kcal mol(-1)(Cr3), 32.4 kcal mol(-1)(Mn3), 61.5 kcal mol(-1)(Fe3), 78.0 kcal mol(-1)(Co3), 86.1 kcal mol(-1)(Ni3), 26.8 kcal mol(-1)(Cu3), and 4.5 kcal mol(-1)(Zn3).