Microcrystallization and lattice contraction of NiFe LDHs for enhancing water electrocatalytic oxidation

Abstract

The lattice-oxygen-mediated mechanism is considered as a reasonable mechanism for the electrochemical catalytic oxygen evolution reaction (OER) of NiFe layered double hydroxides (LDHs). A NiFe LDH with distinct lattice contraction and microcrystallization was synthesized via a

Regulating Ni3+ contents by a cobalt doping strategy in ternary NixCo3−xAl1-LDH nanoflowers for high-performance charge storage

“…Furthermore, two satellite peaks located at 862.1 and 879.8 eV can also correspond to the shake-up peaks of Ni 2p 3/2 and Ni 2p 1/2 , respectively. 28 For Ni x Co 3− x Al 1 -LDHs, the fitting peaks at 856 and 873.3 eV are indexed to Ni 2+ , while the fitting peaks at 857.2 and 876 eV are ascribed to Ni 3+ . 29 From Ni 2 Co 1 Al 1 -LDH to Ni 1 Co 2 Al 1 -LDH, the ratio of Ni 3+ to Ni 2+ increased significantly (Table 3), indicating that the increase of Co content promotes the formation of more Ni 3+ species in Ni x Co 3− x Al 1 -LDHs.…”

Volcano relationships and a new activity descriptor of 2D transition metal–Fe layered double hydroxides for efficient oxygen evolution reaction

“…This could have resulted from different intercalated anions into the interface layers for transition metal hydroxides. 61,62 For the Co 1Àx Fe x -LDHs with higher Fe contents (Co 0.71 Fe 0.29 and Co 0.64 Fe 0.36 ), the peaks belonging to the Co(OH) 2 LDH at 51.51 (320) and the hydrotalcite-like structure at 40.61 (012) and 73.51 (113) became stronger, indicating that more Fe ions were incorporated in the Co(OH) 2 LDH matrix structure and rearranged into a more hydrotalcite-like crystal structure. 63 Similarly, the higher Fe-content in Ni 0.65 Fe 0.35 and Ni 0.56 Fe 0.44 also led to an increased intensity for the hydrotalcite-like LDH peak at 54.51 (018).…”

Boosting electrocatalytic water oxidation of NiFe layered double hydroxide via the synergy of 3d–4f electron interaction and citrate intercalation

“…Bimetallic hydroxides, such as NiFe layered double hydroxides (LDHs), have emerged with great potential for alkaline OER due to their superb catalytic activity, low cost, and high structural reversibility. [17][18][19] Lots of efforts have been made to reveal the interactions between nickel and iron atoms of NiFe-LDH and thus enhance the intrinsic OER activity. Shao et al introduced a series of transition metal atoms (Ti, V, Cr, Mn, Co, Cu, Zn, Mg, and Al) to NiFe host layers to promote electron transfer and increase the conductivity.…”