CuO Nanosheets for Use in Photoelectrochemical Photodetectors

Metal oxide semiconductors have attracted growing attention due to their excellent electrical and optical properties, low-cost fabrication, and good stability, which grant them great band photoelectrochemical (PEC)-type PDs based on metal oxide semiconductors are deficient. In this work, we synthesized twodimensional (2D) CuO nanosheets (NSs) by annealing Cu-based metal-organic frameworks (Cu-MOFs) and first demonstrated broadband PEC PDs based on 2D CuO NSs. The thicknesses of 2D CuO NSs are 2-6 nm. 2D CuO PEC PDs show a broadband photoresponse from 365 to 850 nm with a responsivity of 2.7 mA/W and a response time of 60/400 ms, which surpass most 2D material-based PEC PDs. Moreover, CuO NSs PEC PDs exhibit outstanding multicycle stability and long-term stability for 1-month storage with negligible decay, exceeding all recently reported 2D material-based PEC PDs. These results endow 2D CuO NSs with great potential in underwater photodetection.

Automated summary

Metal oxide semiconductors have attracted increasing attention due to their excellent electrical and optical properties, low-cost fabrication, and good stability. In this study, two-dimensional CuO nanosheets were synthesized by annealing Cu-based metal-organic frameworks (Cu-MOFs) and broadband photoelectrochemical photodetectors (PDs) based on these nanosheets were demonstrated for the first time. The 2D CuO PDs exhibited a wide photoresponse range from 365 to 850 nm, with a responsivity of 2.7 mA/W and a response time of 60/400 ms, surpassing most existing 2D material-based PDs. Moreover, the CuO PDs showed outstanding multicycle stability and long-term stability for 1-month storage, outperforming other 2D material-based PDs reported to date. These results suggest great potential for 2D CuO nanosheets in underwater photodetection.