The aim of the present study is to investigate BiVO₄ sensing electrode (SE) based electrochemical gas sensor for ammonia (NH₃) sensing. Additionally, this study is also focused to reduce the operating temperature of sensor by applying different electrolytes i.e., yttria stabilized zirconia (YSZ) and gadolinia doped ceria (GDC). The maximum sensor response obtained for YSZ and GDC based cells towards 80 ppm NH₃ were − 103.03 and − 78.81 mV at 600 ℃ and 550 ℃, respectively. Corresponding sensitivity of YSZ and GDC based cells for NH₃ sensing were − 99.24 and − 42.66 mV/decade, respectively. Both the sensors demonstrate excellent selectivity as well as stability against 80 ppm NH₃ (10 cycles) and humidity variation (pH₂O = 0–0.12 atm.). Electrochemical impedance spectra (EIS) and dc polarization (I-V) curves confirms the mixed-potential sensing mechanism of the sensors. The systematic dependency of electrode’s resistance at a given frequency on the gas concentration reveals a novel pathway for prediction of sensors’ behavior. Additionally, the presence of GDC electrolyte decreases the response/recovery time (16/125 s) compared to YSZ-based cells (21/159 s) against 320 ppm NH₃ at 550 ℃ which demonstrate its low temperature sensing capability. This 50 ℃ reduction in the operating temperature can be useful for extension of lifetime of sensor.

本研究的目的是研究基于 BiVO ₄传感电极 (SE) 的电化学气体传感器用于氨 (NH ₃ ) 传感。此外，本研究还侧重于通过应用不同的电解质（即氧化钇稳定氧化锆（YSZ）和氧化钆掺杂氧化铈（GDC））来降低传感器的工作温度。在 600 ℃ 和 550 ℃ 下，基于 YSZ 和 GDC 的电池对 80 ppm NH _{3获得的最大传感器响应分别为 - 103.03 和 - 78.81 mV。}基于 YSZ 和 GDC 的电池对 NH ₃传感的相应灵敏度分别为 - 99.24 和 - 42.66 mV/decade。两种传感器都表现出出色的选择性以及对 80 ppm NH _{3的稳定性}（10 个循环）和湿度变化（p H ₂ O = 0–0.12 atm.）。电化学阻抗谱 (EIS) 和直流极化 (IV) 曲线证实了传感器的混合电位传感机制。给定频率下电极电阻对气体浓度的系统依赖性揭示了一种预测传感器行为的新途径。此外，与基于 YSZ 的电池 (21/159 s) 相比，在 550 ℃ 下，GDC 电解质的存在降低了响应/恢复时间 (16/125 s)，_这证明了其低温传感能力。工作温度降低 50 ℃ 有助于延长传感器的使用寿命。