As well been documented, the water splitting is severely hindered by oxygen evolution reaction (OER) which is a kinetically sluggish reaction with 4e- transfer. Currently, RuO2 and IrO2 are well-known to be efficient for OER, but their scarcity and high cost limit their widespread applications. Fortunately, many transition-metal based catalysts show great potential as alternate catalysts for OER because of their good water oxidation performance and earth-abundant nature. However, due to auto-oxidation under a high oxidation potential, the active components are easy to agglomerate and dissolve, resulting in a decrease in electrochemical activity. Therefore, it is highly desirable to develop highly efficient and stable noble-metal-free OER catalyst. Herein, uniform hollow bimetallic phosphides confined within carbon layers (NiFeP@C) were synthesized through a two-step process. SEM and TEM imagesin Figure 1a-d revealed that the as-formed NiFe@C and NiFeP@C product showed an average length of about 2.5 µm but NiFeP@C sample displayed hollow elongated bipyramid structure. Moreover, the as prepared catalysts were tested for the performance in OER as shown in Figure 2a-b. Compared with NiFe@C and commercial IrO2 catalyst, the NiFeP@C catalyst exhibited enhanced (OER) performance with a low overpoential of 256 mV to achieve the current density of 10 mA cm-2 and an excellent stability. Such high activity and stability indicate that NiFeP@C with hollow structure, carbon-encapsulated active composition, and low cost may be a good candidate as electrocatalyst in the practical application of OER.

Hollow NiFeP@C derived from metal-organic framework for enhanced oxygen evolution reaction

2019 Spring National Meeting

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