The integration of Fe dopant and interfacial FeOOH into Ni-MOFs [Fe-doped-(Ni-MOFs)/FeOOH] to construct Fe-O-Ni-O-Fe bonding is demonstrated and the origin of remarkable electrocatalytic performance of Ni-MOFs is elucidated. X-ray absorption/photoelectron spectroscopy and theoretical calculation results indicate that Fe-O-Ni-O-Fe bonding can facilitate the distorted coordinated structure of the Ni site with a short nickel-oxygen bond and low coordination number, and can promote the redistribution of Ni/Fe charge density to efficiently regulate the adsorption behavior of key intermediates with a near-optimal d-band center. Here the Fe-doped-(Ni-MOFs)/FeOOH with interfacial Fe-O-Ni-O-Fe bonding shows superior catalytic performance for OER with a low overpotential of 210 mV at 15 mA cm and excellent stability with ≈3 % attenuation after a 120 h cycle test.
View Article and Find Full Text PDFThe intrinsic activity of NiFe layer double hydroxides (LDHs) for the oxygen evolution reaction (OER) suffers from its predominantly exposed (003) basal plane, which is thought to have poor activity. Herein, we construct a hierarchal structure of NiFe LDH nanosheet-arrays-on-microplates (NiFe NSAs-MPs) to elevate the electrocatalytic activity of NiFe LDHs for the OER by exposing a high-activity plane, such as the (012) edge plane. It is surprising that the NiFe NSAs-MPs show activity of 100 mA cm at an overpotential () of 250 mV, which is five times higher than that of (003) plane-dominated NiFe LDH microsheet arrays (NiFe MSAs) at the same , representing the excellent electrocatalytic activity for the OER in alkaline media.
View Article and Find Full Text PDFThe multi metal organic frameworks (BTC-CoNiFeZn) were used as the precursors of in situ structure reconstruction in alkaline solution, and we synthesized hierarchical porous Ni,Fe-codoped Co-hydroxide nanowire array (Ni0.8Fe0.2/Co-H NAs/NF) catalyst for the oxygen evolution reaction (OER).
View Article and Find Full Text PDFThe development of efficient electrocatalysts for overall water splitting is important for future renewable energy systems. Herein, macroporous CoO covered by Co/N-doped graphitic carbon nanosheet arrays (mac-CoO@Co/NGC NSAs) were constructed by engineering a mesoporous CoO nanowire (mes-CoO NWAs) core with highly conductive Co nanoparticles coated by a N-doped graphitic carbon (Co/NGC) shell. The in situ derived Co/NGC shell not only introduces electrocatalytic active sites for the hydrogen evolution reaction (HER) but also promotes the oxygen evolution reaction (OER) through the strong interaction between the CoO core and the Co/NGC shell.
View Article and Find Full Text PDFPorous CoFe O /C NRAs supported on nickel foam@NC (denoted as NF@NC-CoFe O /C NRAs) are directly fabricated by the carbonization of bimetal-organic framework NRAs grown on NF@poly-aniline(PANI), and they exhibit high electrocatalytic activity, low overpotential, and high stability for the oxygen evolution reaction in alkaline media.
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