0D-3D-1D nanoarchitectured CQDs modified NiFe layered double hydroxides supported with MWCNTs: Enhanced electrocatalytic performance for oxygen evolution reaction

Nickel-Iron Layered Double Hydroxides (NiFe LDH)-based electrocatalysts have evinced tremendous interest towards oxygen evolution reaction (OER) to overcome sluggish water oxidation kinetics. This study reports (i) engineering coordination environment of NiFe LDH by varying Ni-Fe ratios (3:1 to 1:3) and (ii) heterostructuring by growing the optimal 1:1 NiFe LDH in situ on multiwalled carbon nanotubes (MWCNT)-modified Ni foam via urea-assisted hydrothermal method and decorating with carbon quantum dots (CQD). The hybrid 0D-CQD/3DNFL/1D-MWCNT shows unique 3D urchin-morphology comprising 2D nanoribbons with an electrochemical surface area of 252.72 cm2/cm2 geometric area and exhibits best overpotential of 172 mV at 100 mAcm- 2, Tafel slope (37.2 mVdec- 1), and stability (1.44V vs. RHE for 100 h at 100 mAcm- 2). Effectively transferring electrons OH- -> through CQDNiFe LDH -*MWCNT-*Ni Foam, the heterostructured CQD/NFL/CNT exhibits minimal change in overpotentials even at higher current densities (204 mV at 500 mAcm- 2 and 212 mV at 750 mAcm- 2), demonstrating its enhanced OER properties.