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 (Cu
₂
O) film with tungsten trioxide nanoparticles (WO
₃
NPs). WO
₃
is a material sensitive to hydrogen and can be used to measure a wide range of pH values. The Cu
₂
O film was prepared using sputtering technology, while the WO
₃
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 WO
₃
NPs modified Cu
₂
O film pH sensor in the pH range of 3 to 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.