λ is the absorbance wavelength in nm. Nitrogen adsorption-desorption for CdS/CTS was carried out using Quantachrom (Model Nova 3200, USA) at -196 o C using liquid nitrogen (N2). CdS/CTS powder was degassed at 110 °C. The pore size distribution analysis was evaluated using Barrett-Joyner-Halenda (BJH), Density Functional Theory (DFT), and Dollimore-Heal (DH). UV-Vis diffuse reflectance spectroscopy (DRS) for CdS, metal salts (CoCl2, Ni(NO3)2, and CuSO4), and CdS/CTS before and after interactions with these metal salts were evaluated using the Evolution 220 spectrophotometer (Thermo Fisher Scientific, UK).