Expanding Multinary Selenide Based High-Efficiency Oxygen Evolution Electrocatalysts through Combinatorial Electrodeposition: Case Study with Fe–Cu–Co Selenides

Abstract

Developing low-cost electrocatalysts with high efficiency for water splitting is a critical task to make this technology viable for large-scale clean energy generation. Transition metal selenides, comprising earth abundant elements, such as Fe, Co and Cu, have gained attention as superior electrocatalysts for oxygen evolution reaction (OER) in the alkaline medium. In this article, we have systematically investigated the evolution of OER catalytic activity as a function of composition for a series of Fe–Co–Cu quaternary selenides by exploring a trigonal phase diagram. The OER activity was dependent on the quantity of Cu and Fe in the Fe-Cu-Co-Se quaternary selenide electrocatalysts, while surprisingly, Fe–Cu ternary selenides exhibit reduced OER activity in comparison to their pure parent compounds FeSe and Cu3Se2. Quaternary selenides exhibited more efficient catalytic activity with increasing amount of Fe or Cu in the catalysts, and the quaternary mixed metal selenide thin film of composition (Fe0.48Co0.38Cu0.14)­Se showed the best catalytic performance with a small overpotential of 256 mV at 10 mA cm–2 and a low Tafel slope of 40.8 mV dec–1 in N2-saturated 1.0 M KOH solution. The outstanding catalytic performance of quaternary selenides may be explained by the possible electron cloud delocalization among the transition metal sites in the catalytic system through d-bands, leading to lower charge transport resistance at the catalyst–electrolyte interface as well better film conductivity, as has also been observed through electrochemical impedance spectroscopy. Such enhanced charge transfers eventually facilitate the rate of O2 release from the catalyst surface, leading to enhanced activity.

Recent Progress on Copper‐Based Electrode Materials for Overall Water‐Splitting

“…Due to the presence of full‐filled d‐levels in Cu I , a substantial amount of Cu doping influences the catalytic activity. In continuation to develop the new transition metal‐based material for OER, recently, transition metal doped quaternary selenides, (Fe 0.48 Co 0.38 Cu 0.14 )Se and (Co 0.21 Ni 0.25 Cu 0.54 ) 3 Se 2 were designed and used as anode material for OER study [44] . Additionally, Cao et al .…”

Recent Advances in Non‐Precious Metal‐Based Electrodes for Alkaline Water Electrolysis

“…In the following section, we will discuss the most widely used strategies that are presently considered promising in improving catalytic performance. [93] Nanoparticles 321 54 (Fe 0.48 Co 0.38 Cu 0.14 )Se [94] Nanoparticles 256 Nanosheet 450 53 NiFeSe@NiSe j O@CC [5] Nanoarray 270 63.2 CoÀ Se [97] Nanoarray 280 (@100 mA/cm 2 ) 40.4 NiSe [98] Nanoarray 290 77.1 Fe-doped NiSe [99] Nanoarray 231 (@50 mA/cm 2…”

Electrodeposition of nanostructured catalysts for electrochemical energy conversion: Current trends and innovative strategies

“…Second to hydroxides, transition metal selenides and phosphides hold potential for improvement and are interesting, especially for overall WS, since they have also good HER performance. Different combinations of multi-metallic (Ni,Fe,Co,Cu) selenides [36][37][38][39] and phosphides [40,41] yield η10 = 230-270 mV and b = 40-60 mV/dec. Combining electrodeposition with other methods, hierarchical structures that combine oxides/hydroxides with phosphides [42], sulfides [43], or rare-earth doped borides [44], have yielded excellent performances (η10 = 200-245 mV, b = 30-40 mV), close to the best reported (oxy)hydroxides.…”

“…Alternatively, transition metal selenides are formed by cathodic co-deposition, normally by continuous PS [36][37][38][39]47] or PS-MP [47] methods. For NiSe, a PS procedure produces smooth films whereas PS-MP yields NPs and NSHs, the latter offering better ECSA and thus OER performance (Fig.…”