Synergistic Effect of Ni and Cu Incorporated CdS Nanoparticles for Photodegradation, Biological Activities, and Molecular Docking Analysis

The present study entails the synthesis of CdS and Ni-Cu incorporated CdS (at 10%, 20%, and 30% concentrations) solid solutions via the chemical co-precipitation method. This investigation delves into the combined impact of Ni and Cu integration into CdS on dye degradation, biological functionalities, and molecular docking analyses. Various techniques were employed to assess the structural, morphological, and optical attributes of the synthesized materials. Analysis of the powder X-ray diffraction (pXRD) spectra indicates the cubic structure of the synthesized CdS and Ni-Cu incorporated CdS solid solutions, with Ni and Cu ions exerting a suppressive effect on the crystallinity of the materials. The size of bare CdS, 10%, 20%, and 30% Cd_1-xNi_xCu_xS (x = 10–30%) codoped cadmium sulfide was 1.04 nm, 1.56 nm, 1.15 nm, and 0.80 nm, respectively. The obtained strains were 2.074 × 10⁻⁴, 3.22 × 10⁻⁴, 2.31 × 10⁻⁴, and 1.39 × 10⁻⁴ for bare CdS, 10%, 20%, and 30% Cd_1-xNi_xCu_xS (x = 10–30%) codoped cadmium sulfide, respectively. The decrease in particle size was due to the different ion radii of constituent ions. In the FTIR spectrum, the sharp peak observed around 648 cm⁻¹ corresponds to the Cd-S stretching band. Tuning of the band gap was achieved, resulting in enhanced photocatalytic degradation of Congo Red dye by Cd₆₀Ni₂₀Cu₂₀S nanoparticles. Cd₆₀Ni₂₀Cu₂₀S nanoparticles have shown a 92% photocatalytic degradation of C. Red dyes under visible light. Notably, Cd₆₀Ni₂₀Cu₂₀S exhibited substantial antibacterial efficacy against Escherichia coli and Lactobacillus bacteria, as well as potent antifungal activity against Aspergillus Niger and Aspergillus Flavous species. The maximum zone of Inhibition of 25 mm and 26 mm was observed with higher nanoparticle concentration. At the same time, the synthesized Cd₆₀Ni₂₀Cu₂₀S nanoparticles also showed enhanced antifungal activity against two fungal stains and showed a noticeable zone of Inhibition of 24 mm and 28 mm with the maximum concentration of nanoparticles, respectively. Additionally, molecular docking analyses were conducted to predict the interaction of CdS and Cd₆₀Ni₂₀Cu₂₀S concerning their antimicrobial activities against Gram-positive (Lactobacillus bacteria) and Gram-negative (Escherichia coli) bacteria, as well as their antifungal activities against Aspergillus Niger and Aspergillus Flavous, utilizing Autodock Vina software. The doped CdS materials exhibited promising antibacterial properties and demonstrated noteworthy antifungal activities.