Enhanced catalytic activity of electrodeposited Ni-Cu-P toward oxygen evolution reaction

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>The slow kinetics of the oxygen evolution reaction (OER) and the high cost of the precious metal catalysts for the OER limit the efficiency and cost-effectiveness of water splitting. In this study, we introduce electrodeposited nickel-copper-phosphorous (NiCuP) as an efficient OER electrocatalyst in alkaline medium. The addition of Cu into the NiP electrocatalyst significantly enhanced the OER activity. Optimization of the electrodeposition conditions revealed that Ni<SUB>59</SUB>Cu<SUB>19</SUB>P<SUB>9</SUB> in terms of atomic percent exhibited the best activity with a reduced Tafel slope and charge transfer resistance for the OER, compared to NiP. The Ni<SUB>59</SUB>Cu<SUB>19</SUB>P<SUB>9</SUB> catalyst successfully endured the OER operation at 10 mA/cm<SUP>2</SUP> for up to 30 h while maintaining a Faradaic efficiency of over 99%. The X-ray photoelectron spectroscopy showed that the amount of active Ni hydroxide (NiOOH) species increased with the addition of Cu, which likely contributed to the enhanced of catalytic activity.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A Ni-Cu-P electrocatalyst for the oxygen evolution reaction (OER) was prepared via electrodeposition. </LI> <LI> The addition of Cu into the NiP electrocatalyst enhanced the catalytic activity, and Ni59Cu19P9 exhibited the maximum OER performance. </LI> <LI> Ni59Cu19P9 required only 307 mV overpotential to deliver 10 mA/cm2 with a 42.5 mV/dec Tafel slope. </LI> <LI> The catalytic activity of Ni59Cu19P9 was sustained for 30 h with almost 100% Faradaic efficiency. </LI> <LI> The increase in the activity with Cu addition is likely associated with the increase in the amount of NiOOH in the NiCuP. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>