Membrane electrode electrolytic cell for in-situ Raman testing. • Window material: quartz wafer or sapphire. • Plate material: high-purity titanium plate; customized high-purity nickel plate is available upon experimental demands for superior corrosion resistance in alkaline solutions. • Tab material: gold-plated copper to improve electrical conductivity and reduce resistance. • Connector type: PEEK quick connector, 1/8 inch British standard; corrosion-resistant with enhanced internal shear force. • Channel size: 14*14 mm, custom sizes are acceptable. • Distance from window sheet to sample: less than 5 mm.