Process optimization and synthesis of lanthanum-cobalt perovskite type nanoparticles (LaCoO3) prepared by modified proteic method: Application of response surface methodology

Due to increasing interest in the application of perovskites as promising adsorbents, the present study looks at how central composite design (CCD), a subset of response surface methodology (RSM), can statistically play a role in producing optimum lanthanum oxide-cobalt perovskite type nanoparticles (LaCoO3) by using a modified proteic synthesis method. The optimum LaCoO3 produced was tested for its capability in removing methyl orange (MO) and rhodamine B (RhB) dyes from aqueous solution. Calcination temperature and calcination time were optimized with the responses being percentage yield, MO and RhB removal. The best temperature and calcination time obtained were 775 degrees C and 62 mins, respectively, giving good and appreciable values for the three responses. The resulting optimal LaCoO3 was characterized by Fourier transform infra-red (FTIR), ultraviolet-visible spectrophotometry (UV/vis), scanning electron microscopy (SEM), pH of zero point charge (pH(pzc)) as well as BET analysis, yielding a mesoporous adsorbent with surface area of 61.130 m(2) g(-1) as well as 223.55 and 239.45 mg g(-1) as the monolayer adsorption capacity values for MO and RhB, respectively. Freundlich model was the best in describing the equilibrium adsorption data with respect to both MO and RhB with the kinetic data for the two dyes both obeying pseudo-second-order kinetics model.