Cu2O/TiO2 Heterostructure-Based Photoelectrochemical Photodetector with Enhanced Performance and Stability

Cu2O/TiO2 heterostructure is prepared by electrodepositing Cu2O on rutile phase TiO2 particles. The morphology, structural, and optical properties of Cu2O/TiO2 heterostructure are determined by scanning electron microscopy, Raman spectroscopy, X-ray diffractometer, and UV-vis absorption spectrum. The Cu2O/TiO2 heterostructure photoelectrochemical-type photodetector is constructed based on this heterostructure. Experimental results show that the photoresponsivity and visible light absorption of the Cu2O/TiO2 heterostructure are significantly enhanced compared to those of TiO2 and Cu2O which demonstrate that the Cu2O/TiO2 heterostructure with a special interfacial structure is conducive to accelerating the separation and transfer of photogenerated carriers. The photoresponsivity and photocurrent density of Cu2O/TiO2 can reach 154 mu A W-1 and 15.6 mu A cm(-2) at 0 V. In addition, the photocurrent density of the Cu2O/TiO2 heterostructure steadily increases with the enhancement of irradiation power density. Moreover, no significant attenuation of the photocurrent density is observed in the prepared Cu2O/TiO2 heterostructure after 1800 s of photo-on/off cycles. These results suggest that the Cu2O/TiO2 heterostructure-based photodetector holds great potential in the photodetection field.