Ag/ZnO Catalysts with Different ZnO Nanostructures for Non‐enzymatic Detection of Urea

• DOI: 10.1002/elan.201800595
• Publication Date: 2018-09-27T09:40:42Z
• Authors: Jaesik Yoon; Doohee Lee; Eunji Lee; Young Soo Yoon; Dong‐Joo Kim
• Keywords: 02 engineering and technology; 0210 nano-technology

AbstractSilver coated ZnO nanorods and nanoflakes with different crystallographic orientations were synthesized by a combination of sputter deposition and solution growth process. Catalytic properties of morphology‐dependent Ag/ZnO nanostructures were then investigated for urea sensors without enzyme. Ag/ZnO nanorods on carbon electrodes exhibit a higher catalytic activity and an improved efficiency than Ag/ZnO nanoflakes on carbon electrodes. Ag/ZnO nanorod catalysts with more electrochemically surface area (169 cm2 mg−1) on carbon electrode facilitate urea electrooxidation due to easier electron transfer, which further promotes the urea electrolysis. The Ag/ZnO nanorod catalysts also show a significant reduction in the onset voltage (0.410 V vs. Ag/AgCl) and an increase in the current density (12.0 mA cm−2 mg−1) at 0.55 V vs Ag/AgCl. The results on urea electrooxidation show that Ag/ZnO nanostructures can be a potential catalyst for non‐enzymatic biosensors and fuel cells.