The construction of defective FeCo-LDHs by in-situ polyaniline curved strategy as a desirable bifunctional electrocatalyst for OER and HER

Two-dimensional FeCo2O4 nanosheets with oxygen vacancies enable boosted oxygen evolution

“…In order to study the effect of oxygen vacancies on the electrocatalytic OER, the electrochemical performances of ). The FeCo 2 O 4 -OV nanosheets with oxygen vacancies have a competitive electrocatalytic performance for water oxidation in alkaline electrolyte compared with other state-of-the-art electrodes, such as FeCo 2 O 4 @NPC-450 1C (330 mV@10 mA cm À2 ), 30 FeCo 2 O 4 nanoparticles (478 mV@10 mA cm À2 ), 44 FeCo 2 O 4 /CeO 2 heterostructures (492 mV@10 mA cm À2 ), 45 FeCo-LDH/ PANIs (285 mV), 46 Ce-doped LaCoO 3 perovskite oxide (380 mV), 47 K 0.8 Na 0.2 (MgMnFeCoNi)F 3 (320 mV), 48 Meanwhile, the existence of an oxygen vacancy also promotes the kinetics and electron transfer rate during the OER process. 50,51 The electrochemical active surface areas (ECSA) of the FeCo What's more, long-term stability is an important consideration for catalysts in practical applications.…”

“…The FeCo 2 O 4 -OV NSs electrode shows a considerable polarization current density of 40 mA cm −2 at 1.60 V vs. RHE, which is 17.4 times as high as that of the original FeCo 2 O 4 NSs (2.3 mA cm −2 ). The FeCo 2 O 4 -OV nanosheets with oxygen vacancies have a competitive electrocatalytic performance for water oxidation in alkaline electrolyte compared with other state-of-the-art electrodes, such as FeCo 2 O 4 @NPC-450 °C (330 mV@10 mA cm −2 ), 30 FeCo 2 O 4 nanoparticles (478 mV@10 mA cm −2 ), 44 FeCo 2 O 4 /CeO 2 heterostructures (492 mV@10 mA cm −2 ), 45 FeCo-LDH/PANIs (285 mV), 46 Ce-doped LaCoO 3 perovskite oxide (380 mV), 47 K 0.8 Na 0.2 (MgMnFeCoNi)F 3 (320 mV), 48 and (BSCF) 3/4 [KM(II)F 3 ] 1/4 solid solution (345 mV). 49 The corresponding Tafel slopes of the FeCo 2 O 4 NSs and FeCo 2 O 4 -OV NSs were also recorded, and the results are depicted in Fig.…”

Recent Progress on Transition Metal Based Layered Double Hydroxides Tailored for Oxygen Electrode Reactions

“…It is worth mentioning that one of the first reports, in 1983, on the electrocatalytic performance of metal hydroxides, revealed a good OER activity of α-Ni(OH) 2 [57], and it was further confirmed that the Fe impurities in the α-Ni(OH) 2 greatly lower the OER overpotential [58,59]. Since then, the LDHs of 3d iron group metals (Fe, Co and Ni)-such as Ni-Fe [60][61][62][63][64], Ni-Co [65][66][67][68], Co-Ni [69][70][71], Fe-Ni [72][73][74], Fe-Co [75][76][77][78], and Co-Co [79][80][81][82]-and the corresponding derivatives-e.g., NiFe 2 O 4 [83][84][85][86], CoFe 2 O 4 [87], NiCo 2 O 4 [88,89], and Co 3 O 4 [90][91][92]-have been employed as OER or bifunctional ORR/OER electrocatalysts with high kinetics in alkaline solution.…”

Layered FeCoNi double hydroxides with tailored surface electronic configurations induced by oxygen and unsaturated metal vacancies for boosting the overall water splitting process

“…42,43 For overcoming these limitations, some modification strategies have been developed for improving the electrocatalytic activity of 2D-LDH materials through enhancing the active site density, improving the intrinsic electrochemical conductivity, and reducing the reaction barrier. The modification methods include defect engineering, 44,45 heteroatom doping, 46,47 structural design, 48,49 and so on. These methods can provide efficient channels to regulate the surface electronic structures to accelerate the electrocatalytic reaction kinetics and improve the performance.…”