Sulfide@hydroxide core–shell nanostructure via a facile heating-electrodeposition method for enhanced electrochemical and photoelectrochemical water oxidation

Designing low-cost,easy-fabricated,highly stable and active electrocatalysts for oxygen evolution reaction(OER) is crucial for electrochemical(EC) and solar-driven photoelectrochemical(PEC) water splitting.By using a facile heating-electrodeposition method,here we fabricated a porous but crystalline Fe-doped Ni3 S2.A thin porous surface NiFe hydroxide layer(~10 nm) is then formed through OER-running.By virtue of the core Fe-doped Ni3 S2 with good conductivity and the shell NiFe hydroxide surface with good electrocatalytic activity,the core-shell nanostructure on Ni foam exhibits excellent OER activity in 1 M NaOH,needing only 195 and 230 mV to deliver 10 and 100 mA/cm^(2),respectively,much more superior to those of 216 and 259 mV for the sample deposited under normal temperature.The enhanced photo-response of the sulfide@hydroxide core-shell structure was also demonstrated,due to the efficient transfer of photo-generated carriers on the core/shell interface.More interestingly,it shows a good compatibility with Si based photoanode,which exhibits an excellent PEC performance with an onset potential of 0.86 V vs.reversible hydrogen electrode,an applied bias photon-to-current efficiency of 5.5% and a durability for over 120 h under AM 1.5 G 1 sun illumination,outperforming the state-of-the-art Si based photoanodes.