Polyaniline film decorated with cadmium sulfide- NrGO nanosheet heterostructure hybrid as highly efficient photoelectrocatalyst for water splitting

Cadmium sulfide (CdS) quantum dots and CdS- nitrogen functionalized reduced graphene oxide (CdS-NrGO) were assembled on polyaniline (PANI)- coated FTO glass to obtain sufficient photoanodes for solar photoelectrochemical (PEC) water splitting and oxygen generation. The PANI film was electrodeposited on FTO glass in the electrochemical cell. The CdS and CdS-NrGO nanocomposites were deposited on PANI- coated FTO glass via spin coating. The as-prepared photoanodes were evaluated by physical and PEC measurements. The obtained FTO/PANI/CdS-NrGO heterostructure photoanode indicated considerably improved photoelctrocatalytic activity for oxygen generation from water splitting in comparison with FTO/PANI and FTO/PANI/CdS photoanodes. The FTO/PANI/CdS-NrGO photoanode displayed a photocurrent density (J) of 18.73 mA cm⁻² (at 1.23V vs. reversible hydrogen electrode (RHE)) for oxygen generations, which was 3.3 and 1.3 times higher than those obtained for FTO/PANI and FTO/PANI/CdS photoanodes, respectively. The improved photoelectrocatalytic performance of this photoanode can be attributed to several positive factors, such as the tiny size impact of CdS quantum dots, the extremely high active sites of the NrGO, and the effective contact between CdS quantum dots and PANI, leading to a downturn in the recombination of photogenerated electron-hole pairs, and the lowest migration resistance of charge carrier.