Tin oxide (SnO2) is an important n-type semiconductor with a large band-gap and has been used as one of the promising materials for gas sensors, optoelectronic devices and negative electrodes for lithium batteries [1]. but recently, many materials ,such as metals , have been introduced to SnO2, which can result in the formation of p-n junctions for enhancement of sensitivity, activity and stability.[2,3] It has been reported that CuO does not react with SnO2 and high sensitivity, good stability has been attributed to p-n junctions formed between n-type SnO2 and p-type CuO [4-6]. So it is necessary to investigate optimum methods for synthesizing of n-Sno2 /p-CuO heterojunction. We report a simple, low-cost environment-friendly hydrothermal and solvothermal synthesise of SnO2 and CuO at low temperature, without any stabiliser and with different molar ratio of SnO2 and CuO. The final material is stable for some month. The samples are characterized with transmission electron microscopy (TEM), x-ray diffraction (XRD), uv-vis absorption spectrum, FT-IR spectroscopy and EDAX.
