Photoelectrochemical engineering of Cu1.94S nanoparticles towards a low temperature atmospheric synthesis method

Cu2−xS photocatalysts have demonstrated robust performance in various applications, including pollutant degradation, sensors, and chemicals synthesis under visible light, owing to their unique properties. Compared to noble-metal-based
photocatalysts, the low cost of copper and sulfur makes Cu2−xS photocatalysts attractive for industrial use. However, developing a simple and scalable synthesis method remains a challenge. In this study, a low-temperature, atmospheric-
pressure route was introduced to synthesize Cu1.94S nanoparticles. XRD analysis confirmed that using Tween 20 as a capping agent at 60 °C yields Cu1.94S nanoparticles, whereas using Triton X-100 under the same conditions results in CuS.FESEM and TEM images revealed that the Cu1.94S nanoparticles are spherical with a strong tendency to aggregate. UV–Vis and photoluminescence analyses showed that the band gap of Cu1.94S could be tuned through this method, reaching a value of 1.66 eV. Furthermore, linear sweep voltammetry and electrochemical impedance spectroscopy indicated a significant enhancement in the electrochemical performance of Cu1.94S-coated electrodes compared to bare titanium electrodes.