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

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