Photo Catalytic Activity of Mn-N Co-Doped ZnsNanoparticles for Degradation of Organic Pollutant (METHYLENE BLUE)

Abstract

Nanoparticles of undoped ZnS, Mn-doped-ZnS, N-doped-ZnS and Mn-N co-doped ZnS were prepared by using chemical co-precipitation method. The precursors used to synthesize the photo catalyst nanoparticles were: Zn (CH3COO) 2.2H2O, Mn (CH3COO) 2.4H2O and Na2S.9H2O. The characterization of nanoparticles was done using X-ray powder diffraction (XRD) and UV–VIS Spectrophotometric technique. The average crystalline size of as-synthesized photo catalysts calculated using the Debye- Scherrer formula was 7.80, 7.48, 6.61 and 6.59 nm for 60 for uncalcined zinc sulfide (Znc), calcined zinc sulfide (Zc), Mn-doped zinc sulfide (MZ), N-doped zinc sulfide (NZ) and Mn-N co-doped zinc sulfide (MNZ) respectively. The percentage degradation of methylene blue under UV irradiation at 180 minutes was: 10.12, 24.85, 45.19, 38.09, and 55.60 for Znc, Zc, MZ, NZ and MNZ respectively. Under solar irradiation the Percentage photo degradation of MB were: 13.53, 30.17, 49.00, 57.30 and 70.75 for Znc, Zc, MZ, NZ, and MNZ respectively. The pseudo first order rate constant (k) of MB photo degradation for Znc, Zc, NZ, MZ, and MNZ were 5.72 × 10-4, 1.64× 10-3, 2.54× 10-3, 3.23× 10-3 and 4.48 × 10-3 min-1 and 0.8×10-3, 2.15×10-3, 4.16×10-3, 5.3×10-3 and 8.66×10-3 min-1 under UV irradiation and under solar irradiation, respectively.