Synthesis Of CdS@CdIn₂S₄ Nanoflake Arrays And Application On Photoelectrochemical Water Splitting

Despite the expected optoelectronic properties of CdS that is suited for a photoanode material,limited by its unstable valence band comosed of S 3p orbitals,its low photochemical stability in liquid electrolytes hampers its candidacy as a photoanode for sustained hydrogen generation from PEC cell.it is thus highly desirable to address the problem associated with the photocorrosion of the CdS photoanode through surface passivated.We emoloyed in-situ gas-phase cation exchange method to fabricate CdS@CdIn₂S₄ NFAs as photoanodes for PEC water splitting.We demonstrated the advantages of CdS@CdIn₂S₄ NFAs as photonaodes for PEC water splitting and also clarified the mechanisms through some techniques include transient absorption spectroscopy,impedance spectroscopy,transient photocurrent spectroscopy,open circuit photovoltage decay spectra,X-ray photoelectron spectroscop and so on.The main results and achievement are as follows:1.The CdS@CdIn₂S₄ NFAs was successfully fabricated by in-situ gas-phase cation exchange method and produced a great photocurrent density of 5.5 mA/cm² in0.25M Na₂S/0.35M Na₂SO₃ electrolyt and the protected electrodes retained 78%of their initial photocurrent during 10 h hydrogen evolution in0.25M Na₂S/0.35M Na₂SO₃ electrolyt compared with the 8%retention of the bare electrode,which boost the photocurrent and improve the photostability simultaneously.2.We demonstrate that the type II junction formed between CdS NFAs and CdIn₂S₄ suface layer,which led to all-round efficient charge spearation and enhanced interfacial charge transfer.And CdIn₂S₄ also increases the conductivity for efficient charge transport.,thus achieved significant PEC improvements.