Tannic acid stabilized antioxidation copper nanoparticles in aqueous solution for application in conductive ink

Water-dispersible copper nanoparticles (Cu NPs) with good antioxidation properties are facilely synthesized in aqueous solution without inert gas protection employing tannic acid (TA) as the stabilizer and protectant. The sizes of as-prepared tannic acid capped copper nanoparticles (TA-Cu NPs) are in the range of 20-40nm with a narrow size distribution. Owing to the protection of TA layer, TA-Cu NPs exhibit excellent anti-oxidation power and no oxidation was observed even after being stored under ambient conditions for 90 days. In addition, homogenous Cu NPs inks could be synthesized via the simple dispersion of TA-Cu NPs in water, which can be inkjet-printed onto flexible substrates into conductive patterns using a common color printer.