MOF-Derived Zn-Doped CoSe₂ as an Efficient and Stable Free-Standing Catalyst for Oxygen Evolution Reaction

Abstract

Developing highly active electrocatalysts with low cost and high efficiency for oxygen evolution reactions (OER) is important for the practical implementations of hydrogen energy. Here, we report a Zn-doped CoSe nanosheets grown on free-standing carbon fabric collector (CFC), which was synthesized by using a metal-organic framework (MOF) as precursor and followed by a selenylation process. Importantly, the Zn-doped CoSe/CFC electrode exhibited an obviously enhanced catalytic activity for OER in 1 M KOH aqueous solution compared with CoSe/CFC, showing a small overpotential of 356 mV for a current density of 10 mA cm, a small Tafel slope of 88 mV dec, and an excellent stability. The robust and free-standing electrode shows great potential as an economic catalyst for OER applications.

Design Strategies toward Advanced MOF‐Derived Electrocatalysts for Energy‐Conversion Reactions

“…Although the metal ions in MOFs are inclined to be reduced to metal NPs during carbonization, it is still likely to convert the metal ions into compounds directly by selecting appropriate precursors and controlling the annealing conditions. [36,42,43,45,73,74,76,[85][86][87][88][89][90][91][92][93][94][95][96][97][98] The most easily obtained compound is transition metal carbides due to the availability of carbon originating from the decomposition of organic ligands. [36,42,43,45,73,74,76,88,93] The case depicted in Figure 1b supports this point.…”

“…[85,94,97,98] As an illustration, You and co-workers synthesized CoP x (a mixture of CoP and Co 2 P) NPs embedded in N-doped carbon matrices (Co-P/NC) using ZIF-67 as the precursor and template. [98] As can be seen in Figure 4a, upon carbonization, ZIF-67 nanopolyhedrons were transformed to Co NPs embedded in porous N-doped carbon matrices (Co/NC).…”

“…For instance, compositing MOF precursors with conductive supports, such as CNTs, [69,95] graphene, [33,34,92] and carbon fabric, [94] has been widely explored to enhance catalytic activity. Recently, Lai et al reported ZIF-8-derived N-enriched meso-microporous carbon (NEMC) frameworks.…”

“…[16] Currently, precious-metal-based catalysts (i.e., Ir, IrO 2 , and RuO 2 ) are the benchmark electrocatalysts for the OER. [15,16] Again, rationally designed materials derived from MOFs have been widely reported as alternative OER electrocatalysts, [35,80,[94][95][96]98,101,[113][114][115][116] and a summary of the OER performances of recent MOF-derived catalysts is listed in Table 2.…”

Three dimensional carbon substrate materials for electrolysis of water

“…Furthermore, MOF-derived carbon materials are also outstanding candidates for the construction of OER catalysts. Our group prepared a free-standing Zn-doped CoSe 2 grown on the MOF-derived carbon fabric collector (CFC) catalyst for OER [73]. .…”