Effect of Synthesis Method on the Nanostructure and Solar-Driven Photocatalytic Properties of TiO2-CuS Composites

TiO2 nanospheres were synthesized and then modified with copper(II) sulfide (CuS) to form TiO2-CuS-a and TiO2-CuS-b, respectively, by two different loading methods (direct deposition vs bifunctional linker coupling). The structural, morphological, and optical properties of the two different composites TiO2-CuS-a and TiO2-CuS-b were characterized and compared using FESEM, HRTEM, XRD, XPS, BET, and DRS techniques. The TiO2-CuS-b with a regular "spiky-ball-like" structure exhibited enhanced disinfection ability, improved photodegradation performance of organic pollutants, and hydrogen evolution efficiency under solar and UV light as compared to TiO2-CuS-a (direct deposition method) due to its higher effective combination with CuS through the bifunctional linking molecule, l-cysteine. The influence of CuS content, the structure, and the charge-transfer mechanism were systematically investigated by PL, CV, EIS, and EPR techniques.