A Silver-Based Miniature Gas Sensor for Hydrogen Sulfide Detection

Abstract

Hydrogen sulfide ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{H}_{{2}}\text{S}$ </tex-math></inline-formula> ) exists widely in many industrial processes and natural environments. Due to its high toxicity and flammable, detection of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{H}_{{2}}\text{S}$ </tex-math></inline-formula> is critical for safety and health at work place and industrial process control. In this article, we report a novel miniature gas sensor, which has a high selectivity in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{H}_{{2}}\text{S}$ </tex-math></inline-formula> detection. The sensor is based on the principle of silver reacting with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{H}_{{2}}\text{S}$ </tex-math></inline-formula> with a strict condition and a fast speed at high temperature. The limit of detection (LOD) is 1.4 parts-per-million (ppm) in ambient conditions and can be further reduced to ~ppb-lever by improving the working temperature and suppressing the noise of the sensor system. Compared with the conventional <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{H}_{{2}}\text{S}$ </tex-math></inline-formula> sensors, this sensor has advantages of miniaturization, low cost, high selectivity, and excluding electrolytes in the analyte detection.