An innovative system was proposed to overcome the major problem of particles\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\' agglomeration during the solution combustion synthesis (SCS) process by using external oxygen sources, named OSCS. The effect of self-sustained exothermic SCS and OSCS process parameters on the structural properties and antioxidant activity of β-MnO2 nanoparticles were investigated theoretically and experimentally. According to ab-initio molecular dynamic (AIMD), molecular dynamic (MD) simulations and experimental results, the crystallographic parameters, kinetic of phase transformation, thermal stability, microstructure, and the super-lattice defects of SCS and OSCS synthesized β-MnO2 nanoparticles relied on the high established vacuum during the process. Interestingly, the specific surface area (SBET) of the OSCS products was increased ∼ 4 times, and particle size and band-gap (Eg) were significantly decreased. The results showed the synthesized β-MnO2 nanoparticles were non-toxic with a high potential against free radicals; the calculated adsorption energy of O2 on the (110) surface of the standard and SCS synthesized β-MnO2 was about 0.19 and 6.85 eV, respectively.

Keywords