Abstract
An experimental investigation was conducted on the electrochemical generation of arsine from high purity (99.9999%), vapor‐deposited arsenic metal in alkaline solutions. A novel method using high‐sensitivity mass spectrometry (MS) coupled to an electrochemical hydrogen calibration (MS‐HC) cell was employed for quantitative analysis of gaseous products. Applications of this method showed the current efficiency for arsine formation to be 95–97% over two orders of magnitude change in the current density. An independent chemical method involving direct oxidation of arsine by silver nitrate confirmed the current efficiency values obtained with MS‐HC. MS experiments conducted up to 200 atomic mass units reveal that arsine and hydrogen are the only gaseous species produced in the electrochemical reduction of arsenic. A scheme is presented for an on‐demand electrochemical generator system that can provide high‐purity arsine over a wide range of concentrations and flow rates to meet the requirements for practical electronic processing applications.