A comparative study on the photocatalytic activity of MgNiS:Eu3+ and MgNiS:Sm3+ nanoparticles for the degradation of eriochrome black T dye

[Display omitted] •Reflux method was used to successfully synthesize MgNiS:Eu3+ and MgNiS:Sm3+ nanoparticles.•Photocatalytic degradation of Eriochrome Black T Dye was studied.•EBT dye was degraded by MgNiS:Eu+3 and MgNiS:Sm+3 upto 89.34 % and 93.96 % respectively. Discharging synthetic dyes into aquatic ecosystems and soil poses significant threats to marine life and soil fertility, necessitating urgent remediation solutions. Developing efficient photocatalysts for dye degradation has recently garnered significant attention as a viable solution. MgNiS:Eu3+ and MgNiS:Sm3+ nanoparticles were successfully synthesized via the reflux method, exhibiting potential as photocatalytic materials. The synthesized nanoparticles were comprehensively characterized using various analytical techniques such as TEM, SEM, XRD, FTIR, PL, UV and Raman spectroscopy. Their photocatalytic activity was evaluated for degradation of the Eriochrome Black T (EBT) dye, demonstrating potential for environmental remediation. The synthesized nanoparticles exhibited uniform particle sizes, ranging from 31-34 nm, as determined by the Debye-Scherrer equation. Notably, these nanoparticles demonstrated exceptional photocatalytic efficacy in degrading Eriochrome Black T, a notorious textile dye pollutant.MgNiS:Eu3+ and MgNiS:Sm3+ nanoparticles efficiently degraded EBT by 89.34 % and 83.96 %, respectively, at pH 5, 50 mg/L dosage, and 10 ppm initial concentration, within 50 min. The kinetic analysis revealed that the photocatalytic degradation of Eriochrome Black T dye follows pseudo-first-order reaction kinetics. This indicates that the reaction rate is directly proportional to the dye concentration. The Freundlich isotherm model best describes the adsorption data for Eriochrome Black T dye. The outstanding photocatalytic performance of MgNiS:Eu3+ and MgNiS:Sm3+ nanoparticles underscores their potential as efficacious catalysts for the remediation of hazardous dye pollutants, thereby contributing to the advancement of sustainable environmental solutions.