Surface states regulation of sulfide-based photoanode for photoelectrochemical water splitting

Regulating the surface states distribution on the photoanode/electrolyte interface is crucial to photo electrochemical (PEC) water splitting. Here we develop a CdIn2S4/InOx/NiFe-LDH adaptive junction to improve the PEC performance and stability of bare CdIn2S4, which achieves a photocurrent density of 5.47 mA cm(-2) at 1.23 V-RHE as well as good durability under AM 1.5G illumination without sacrificial reagent. The experimental characterizations evidence that both the charge carrier density (N-d) and surface states distribution (N-ss) alter along with the interfacial structural regulation in the CdIn2S4/InOx/NiFe-LDH photoanode, and a proper ratio of N-ss/N-d guarantee the optimal photocurrent. Meanwhile, a strained surface states distribution and negative shifted N-ss center facilitate the charge transfer and interfacial water oxidation kinetics as well. This work highlights the influence of interfacial structural regulation on the entangled surface states distribution and charge carrier density and may inspire more excellent work on designing other efficient photoanodes.

Automated summary

Regulating the surface states distribution on the photoanode/electrolyte interface is crucial to photoelectrochemical water splitting. The development of a CdIn2S4/InOx/NiFe-LDH adaptive junction improves PEC performance and stability, with experimental characterizations showing the influence of interfacial structural regulation on surface states distribution and charge carrier density.