Co2P Nanoparticles Wrapped in Amorphous Porous Carbon as an Efficient and Stable Catalyst for Water Oxidation

Abstract

Exploring highly active, enduringly stable, and low-cost oxygen evolution reaction catalysts continues to be a dominant challenge to commercialize renewable electrochemical water-splitting technology. High-active and earth-abundant cobalt phosphides are recently considered as promising candidates. However, the poor inherent electron transfer efficiency and instability hinder its further development. In this work, a novel approach was demonstrated to effectively synthesize Co2P nanoparticles wrapped in amorphous porous carbon framework (Co2P/C). Benefiting from extremely high specific surface area of porous carbon, plenty of active sites were adequately exposed. Meanwhile, unique anchoring structure between Co2P nanoparticles and amorphous carbon outerwear insured high charge transfer efficiency and superior stability of Co2P/C. Due to these favorable properties, low overpotential of 281 mV at 10 mA cm−2 and Tafel slope of 69 mV dec−1 were achieved in resultant Co2P/C catalyst. More significantly, it only exhibited a negligible overpotential increase after 30 h stability test, and these performances entirely preceded commercial RuO2 benchmark. In summary, we proposed a simple and feasible strategy to prepare metal phosphides wrapped with amorphous porous carbon outerwear for efficient and durable electrochemical water oxidation.

ZnO‐Templated Selenized and Phosphorized Cobalt‐Nickel Oxide Microcubes as Rapid Alkaline Water Oxidation Electrocatalysts

“…The peaks at 1584 and 2687 cm −1 can be assigned as Co(OH) 2 and Ni(OH) 2 . The peak at 1347 cm −1 may be related to the interaction with carbon in the form of catalyst ink . This provides a clue that in current work that the phosphorized and selenized samples transform into a catalytic active phase, which is in the form of hydroxides.…”

Anchoring γ-MnO2 within β-NiCo(OH)2 as an Interfacial Electrode Material for Boosting Power Density in an Asymmetric Supercapacitor Device and for Oxygen Evolution Catalysis

“…Furthermore, the β-NiCo­(OH) 2 /γ-MnO 2 electrocatalyst possesses a lower Tafel slope of 50.8 mV dec –1 , which is lesser than that of β-NiCo­(OH) 2 /α-MnO 2 (83 mV dec –1 ) (Figure e). Importantly, the Tafel slope of the β-NiCo­(OH) 2 /γ-MnO 2 electrocatalyst is comparable to the commercial IrO 2 and RuO 2 electrocatalysts. , Moreover, the reaction kinetics of OER catalysis was examined by the EIS plot by knowing the open circuit potential at 0.396 V, as shown in Figure f. The β-NiCo­(OH) 2 /γ-MnO 2 electrocatalyst shows a minimum R s (0.79 Ω) and R ct (0.49 Ω), which is much lesser than that of β-NiCo­(OH) 2 /α-MnO 2 electrocatalysts ( R s , 1.02 and R ct , 0.53 Ω).…”

“…2 /γ-MnO 2 electrocatalyst is comparable to the commercial IrO 2 and RuO 2 electrocatalysts 52,53. Moreover, the reaction kinetics of OER catalysis was examined by the EIS plot by knowing the open circuit potential at 0.396 V, as shown in Figure9f.…”

Recent Developments on Cr‐Based Electrocatalysts for the Oxygen Evolution Reaction in Alkaline Media

“…Among the transition metal phosphides, Co containing phos- phides have been attracting a fair amount of attention as bifunctional electrocatalysts. [96][97][98][99][100][101] Wu and co-workers studied the effect of doping Co 2 P with Cr on carbon black (Cr x Co 2-x P-CB) and the resultant activity towards catalysing both the HER and OER. [53] The low electronegativity of the Cr 3 + was sought-after for improving the charge transfer and modulating the chemisorption strength of OER intermediates on Co 2 P. No evidence of CrP characteristic peaks were observed in the XRD patterns, however a positive peak shift for Cr x Co 2-x P/CB is evident when compared to Co 2 P/CB.…”