Designing an eco-friendly Co/MnS/S-g-C₃N₄ nanocomposites: revolutionizing photocatalytic dye degradation and antibacterial efficiency

초록

This study utilized an eco-friendly, simple, and cost-effective co-precipitation method to synthesize pure MnS and a series of Co/MnS nanoparticles (NPs) with varying cobalt contents (2%, 4%, 6%, 8%, and 10%). Thiourea was calcined at 552 degrees C to prepare S-g-C3N4 (SCN) nanosheets. The optimal doped NPs were combined with S-g-C3N4 to create a series of nanocomposites (10%, 30%, 50%, 70%, and 90%). The materials band gap (Eg) values were determined using Tauc plots. Photodegradation of MB dye was conducted with a UV-Vis spectrophotometer. According to the best of our knowledge, Sulfur-doped graphitic carbon nitride (S-g-C3N4) has been used for the first time in combination with cobalt and manganese sulfide nanoparticles to synergistically enhance visible-light photocatalytic activity, enabling efficient degradation of a toxic organic dye methylene blue. Besides photocatalytic treatment, the antibacterial results reveal that (Co /MnS/ S-g-C3N4) effectively destroyed bacteria with a synergy effect among cobalt elements, MnS and S-g-C3N4. Results indicated that doping 6% cobalt into the MnS lattice enhanced photocatalytic oxidation/reduction. The highest photodegradation performance was observed in 6% Co/MnS@10% SCN nanocomposites, attributed to improved charge separation and reduced charge recombination. The synthesized nano-catalysts maintained significant degradation percentages even after three cycles. The structural morphologies of pure MnS, 6% Co/MnS, S-g-C3N4, and 6% Co/MnS@ 10% SCN nanocomposites were analyzed using XRD and FTIR. Kinetic studies of the prepared nanomaterials were conducted to determine their rate constants. The antibacterial performance of the best photocatalysts was tested against Bacillus subtilis and Escherichia coli. The results suggest that composite synthesis and doping enhanced the antibacterial activity of MnS, with the trend for antimicrobial activity being MnS < 6% Co/MnS < 6% Co/MnS@10% SCN.

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