Hongjun Liu1 Mari-Ann Einarsrud2 David Munoz-Rojas1

1, LMGP Grenoble INP/CNRS, Grenoble, , France
2, NTNU, Trondheim, , Norway

AgCuO2 is a low band gap, p-type semiconducting material in which both silver and copper present intermediate oxidation state. This compound presents a peculiar electronic structure in which charge is delocalized and, as a result, electronic conductivity is much higher than for other p-type oxides.[1] As a result, AgCuO2 appears as an attractive semiconductor for use in optoelectronic applications, in particular photosplitting and all/oxide new generation solar cells.
AgCuO2 can be synthesized by different approaches as bulk powders, including, electrochemical oxidation, oxidation with ozone and oxidative co-precipitation.[2] A hydrothermal approach has also been developed to grow micro-size crystals that allowed the measurement of transport properties in single crystals, using nanocotacts deposited by Focused Ion Beam (FIB).[3] Values of resistivity as low as 10-2 Ωcm were measured in these single crystals. In the synthesis, solid AgO and Cu(NO3)2 are mixed in a basic solution.
We have used a specially designed hydrothermal cell[4] to characterize in situ the reaction mechanism of the hydrothermal formation of AgCuO2 from solid AgO precursor. In this communication we will present the effect of the different experimental parameters on the reaction output. Though this study we have been able to elucidate the formation mechanism of AgCuO2 and to obtain an activation energy for the reaction. The knowledge obtained from this in situ study sheds light on the formation mechanism of AgCuO2 by other synthetic approaches.
[1] D. Muñoz-Rojas, et al. J. Phys. Chem. B. 36 (2005) 6193–6203.
[2] D. Muñoz-Rojas, et al.s, Mater. Today. 14 (2011) 119–119.
[3] D. Muñoz-Rojas, et al., Inorg. Chem. 49 (2010) 10977–10983.
[4] A.R.M. Dalod, et al., J. Phys. Chem. C. 121 (2017) 11897–11906.