Enhanced photoelectrochemical performance of plasmonic Ag nanoparticles grafted ternary Ag/PaNi/NaNbO3 nanocomposite photoanode for photoelectrochemical water splitting

摘要： In this work, we have successfully synthesized silver nanoparticles (Ag-NPs) decorated binary PaNi/NBO nanocomposite by facile chemisorption route and demonstrated enhanced photoelectrochemical (PEC) water splitting activity. The ternary Ag/PaNi/NBO nanocomposite photoanode exhibits ~5 fold higher current density than pristine NaNbO3 nanofibers (NBO-NFs). The ternary Ag/PaNi/NBO photoanode exhibits a current density of 5.93 mA/cm2 at 0.9 V with respect to Ag/AgCl, whereas the pristine NBO-NFs photoanode exhibits only 0.85 mA/cm2 at 0.9 V. The improved performance is correlated to the high surface area, formation of the type-II heterojunction among PaNi and NBO-NFs and the introduction of the plasmonic behaviour of Ag-NPs as it expands the absorption of the visible part of the solar spectrum, which together decreases the recombination of charges with strong redox capability. Furthermore, the ternary Ag/PaNi/NBO photoanode showed lower charge transfer resistance (Rct) in the EIS measurements and improved incident photon to current efficiency (IPCE) of ~31.3% which is ~23% higher to the IPCE of bare NBO-NFs photoanode. Thus, these results suggest that the ternary Ag/PaNi/NBO nanocomposite is a promising material for PEC activity and wide practical applications.