Cobalt and nickel oxides supported activated carbon as an effective photocatalysts for the degradation Methylene Blue dye from aquatic environment

Oxides supported Activated Carbon (Ox-ACs) was prepared from Calophyllum inopyllum (punnai shell) via two steps activation approach of the physic-chemical process such as pyrolysis (600 °C) followed by acid (H2SO4) respectively. Approximately 0.6% cobalt and nickel oxides were doped on the surface of Ox-ACs, which was confirmed by the potentiometric titration. Cobalt and nickel doped Ox-ACs (Co-Ox-ACs and Ni-Ox-ACs) have been utilized as photocatalysts for the degradation of Methylene Blue (MB) from the aqueous medium. The functional groups, structural morphology and elemental compositions of photocatalysts were characterized using FT-IR, SEM and EDX analysis respectively. Photocatalytic studies of metal undoped and doped ACs were performed using a photocatalytic reactor with UV–visible irradiation, where the minimum MB degradation (5%) was observed for Ox-ACs. The maximum photocatalytic degradation rate (94%) was achieved by the incorporation of the minimal amount (6%) of Co2+ and Ni2+ ions on the surface of Ox-ACs. The kinetic study was evaluated using pseudo-first-order kinetic- Langmuir-Hinshelwood model, obtained data was well fitted to the kinetic model. The recyclability of photocatalysts was examined for five cycles, which confirmed that the very less rate changes was observed by the reproduced catalysts. Co-Ox-ACs and Ni-Ox-ACs are used as an efficient photocatalyst for the effluent dye degradation process. •Co2+ and Ni2+ ions doped Ox-ACs has an efficient photocatalysts.•Photocatalytic activity of Co and Ni-Ox-ACs is much higher than that of Ox-ACs.•Catalytic amount of metal ions (Co2+ and Ni2+) is enough to enhance the photocatalytic activity.•It is seems to be better regeneration capacity in after several cycles.