Research on pH Sensor Based on Cuprous Oxide Film Modified With Tungsten Trioxide Nanoparticles

This study prepared a pH sensor by modifying a cuprous oxide (Cu2O) film with tungsten trioxide nanoparticles (WO3 NPs). WO3 is a material sensitive to hydrogen and can be used to measure a wide range of pH values. The Cu2O film was prepared using sputtering technology, while the WO3 NPs were synthesized through a hydrothermal method. The surface roughness, crystallographic orientation, thickness, and morphological features were analyzed using atomic force microscopy (AFM), X-ray diffractometer (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM). Subsequently, we investigated the sensing performance of the WO3 NPs modified Cu2O film pH sensor in the pH range of 3–11. The research results indicate that the modified pH sensor exhibits a high linearity of up to 0.993 and an average sensitivity of 44.77 mV/pH. Additionally, the sensor demonstrates good response time, excellent repeatability, and low hysteresis voltage. These characteristics highlight the outstanding performance of the pH sensor prepared in this study.