A hydrogen sulfide photoelectrochemical sensor based on BiVO₄/Fe₂O₃ heterojunction

A BiVO₄/Fe₂O₃ heterojunction for non-enzymatic photoelectrochemical (PEC) determination of hydrogen sulfide (H₂S) is reported. The BiVO₄/Fe₂O₃ heterojunction promoted the separation of photo-generated carriers, reduced electron–hole recombination, and thus improved electron collection and photocurrent. The proposed BiVO₄/Fe₂O₃/FTO sensor exhibited a linear range of 1–500 μM and a detection limit of 0.51 nM H₂S. In addition, high selectivity, good reproducibility, and stability were obtained for H₂S sensing. The detection of H₂S in water and serum samples demonstrated its feasibility. This work provides a new strategy to detect and understand the bio-function of H₂S in the biological environment.