Recent advances in photoelectrochemical detection of hydrogen sulfide

Hydrogen sulfide (H 2 S), as a biologically significant gaseous signaling molecule and environmental pollutant, has garnered extensive attention due to its crucial roles in various physiological processes and environmental systems. Photoelectrochemical (PEC) sensing has emerged as a promising analytical strategy for H 2 S detection owing to its high sensitivity, excellent selectivity, and minimal background interference, achieved through effectively coupling specific analyte recognition events with photoinduced electrochemical signals. This review systematically summarizes recent advances in PEC sensing technologies for H 2 S detection, categorized into three main strategies: (i) PEC sensors based on the intrinsic hole-scavenging capability of H 2 S; (ii) PEC platforms constructed via the in situ generation of metal sulfides (such as CdS, Bi 2 S 3 , Ag 2 S, and Cu x S); and (iii) PEC sensors incorporating small organic molecular probes specifically responsive to H 2 S. Detailed discussions include detection principles, sensor configurations, material components, and analytical performance of various PEC sensing systems. Finally, perspectives are provided regarding future opportunities and challenges, including the exploration of novel metal sulfide semiconductors, development of advanced single-atom catalysts for precise recognition of H 2 S, and further optimization of multifunctional organic PEC probes to extend practical applications in environmental monitoring, biomedical diagnostics, and food safety analyses.