High‐Performance Self‐Powered PEC Photodetectors Based on 2D BiVO4/MXene Schottky Junction

Abstract As an emerging field, self‐powered photoelectrochemical (PEC) photodetectors have gradually attracted extensive attention thanks to the unique working characteristics of low preparation cost, strong tunability of device performance, and environmental friendliness. However, short absorption wavelength range, low efficiency of visible light utilization, and low responsivity remain challenges for performance improvements. Here, the PEC photodetectors based on the 2D BiVO 4 /MXene Schottky junction structure, which shows excellent performance with high photocurrent density (≈3.90 mA cm −2 at 0 V SCE under AM 1.5 G, 150 mW cm −2 ), good responsivity (790.2 mA W −1 under 447 nm), fast response time ( t r / t f = 8/14 ms), and long‐term stability (keep 17 000 s and 22 000 cycles) are fabricated. These can be attributed to the built‐in electric field at the BiVO 4 /MXene Schottky junction interface, which accelerates the transfer of photogenerated electrons and holes, and inhibits interfacial charge recombination. Additionally, the MXene nanosheets improve the absorption of visible‐light‐induced photons on the valence band of BiVO 4 . These excellent properties show that this work provides a scientific experimental reference for the further development of PEC photodetectors.