Highly sensitive H_2S gas sensors based on Pd-doped CuO nanoflowers with low operating temperature

摘要

A facile method was used to prepare Pd-doped CuO nanoflowers with various doping concentrations. The samples were characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), inductively coupled plasma atomic emission spectrometer (ICP-AES), and Brunauer - Emmett - Teller (BET) specific surface area analysis. The responses (R_g/R_a or R_a/R_g, where R_g is the resistance in gas, and R_a is the resistance in air) of such sensors exposed to 50 ppm CH_4, NO_2, C_2H_5OH, H_2S, NH_3, and H_2 were measured for comparison. For 1.25 wt% Pd-doped CuO nanoflowers, the response (R_g/R_a) to 50ppm H_2S was 123.4 at 80℃, which was significantly higher than that of pure CuO (R_g/R_a = 15.7). Furthermore, excellent stability and repeatability of the gas sensor were also demonstrated. The observed results clearly revealed that it is an important and facile approach to detect the H_2S at low operating temperature for practical applications.