Ultra-sonication assisted metal chalcogenide modified mesoporous Nickel-cobalt doped manganese oxide nanocomposite fabrication for sono-catalytic dye degradation and mechanism insights

The present study is to demonstrate the molybdenum sulphide (MoS2) modified metal ion doped manganese oxide (MnO2) effect for sono-catalytic dye degradation application. The as-prepared additive (5% and 10% MoS2) modified Nickel-cobalt modified porous Manganese oxide (Ni─Co─MnO2) catalysts have shown complete dye discoloration and good sorption activity due to improved higher surface area values compared to undoped pristine manganese oxide. X-ray diffraction pattern confirms the formation of α-phase of MnO2 with tunnel structure formation due to present synthesis method. The thermal stability and structure-property relationship of prepared catalysts have studied by various physico-chemical methods. The thermal stability of the prepared catalysts have stable up to 500─600 °C with Mn2O3 phase and it is further transform into more stable Mn3O4 phase. The fascinating flaky morphology of MnO2 and nanofibers of MoS2 nanoparticle exfoliation into porous manganese oxide matrix, which is clearly examined by SEM and HR-TEM. The particle size and zeta potential values are described for their respective surface property alteration. The pristine Ni─Co─MnO2 and additive modified catalyst have exhibiting effective and complete degradation for Congo red (CR) dyes after modification by MoS2. The re-peated results are obtained for re-used catalyst for dye degradation in the sono-catalytic process. The sono-catalytic mechanism insights of cong red degradation in the presence of MoS2/Ni─Co─MnO2 catalyst have also been demonstrated. The cycle stability for dye degradation and reusability of the as-prepared catalysts show effective repeating activity up to 95%.