From a Molecular 2Fe‐2Se Precursor to a Highly Efficient Iron Diselenide Electrocatalyst for Overall Water Splitting

Abstract

Ah ighly active FeSe 2 electrocatalyst for durable overall water splitting was prepared from amolecular 2Fe-2Se precursor.T he as-synthesized FeSe 2 was electrophoretically deposited on nickel foam and applied to the oxygen and hydrogen evolution reactions (OER and HER, respectively) in alkaline media. When used as an oxygen-evolution electrode, alow 245 mV overpotential was achieved at acurrent density of 10 mA cm À2 ,r epresenting outstanding catalytic activity and stability because of Fe(OH) 2 /FeOOH active sites formed at the surface of FeSe 2 .Remarkably,the system is also favorable for the HER. Moreover,a no verall water-splitting setup was fabricated using at wo-electrode cell, whichd isplayed al ow cell voltage and high stability.I ns ummary,t he first iron selenide material is reported that can be used as abifunctional electrocatalyst for the OER and HER, as well as overall water splitting.

(Fe0.2Ni0.8)0.96S tubular spheres supported on Ni foam as an efficient bifunctional electrocatalyst for overall water splitting

“…5a , this electrolyzer just requires low cell voltages of 1.56 V and 1.65 V to drive the current density of 10 mA cm −2 and 30 mA cm −2 , respectively. Although the cell voltage of (Fe 0.2 Ni 0.8 ) 0.96 S TSs/Ni couple to generate 10 mA cm −2 is larger than that of the Ni x Co 3-x S 4 /Ni 3 S 2 /NF (1.53 V) 49 , it is superior to those of FeNi-LDH Ss/Ni (1.66 V), RuO 2 –50 wt% Pt/C couple (1.58 V), NiCo 2 S 4 @NiFe LDH/NF (1.60 V) 24 , Ni 0.7 Fe 0.3 S 2 /Ni (1.625 V) 26 , NiCo 2 S 4 /NF (1.68 V) 27 , CoS 2 NTA/CC (1.60 V) 33 , FeSe 2 /NF (1.73 V) 50 , FeB 2 -NF (1.57 V) 51 , Zn 0.76 Co 0.24 S/CoS 2 /TM (1.66 V) 52 and even most of the reported works exhibited in Table S4 . Moreover, H 2 and O 2 with a predicted ratio of 2: 1 are obtained, and the amount of experimentally quantified gas is in good accordance with theoretically calculated gas, indicating that the (Fe 0.2 Ni 0.8 ) 0.96 S TSs/Ni affords a Faradaic efficiency of ~100% for both HER and OER (Fig.…”

Nonprecious metal's graphene‐supported electrocatalysts for hydrogen evolution reaction: Fundamentals to applications

“…Among the nonnoble metal hybrid, metal selenides with a proper d-electron configuration are considered as the promising electrocatalysts. 91,92 For example, density functional theory (DFT) calculations exhibit that the transition metal selenides edges are active sites for HER. To promote the electrocatalytic performance of nonnoble metal selenides, it is essential to create defects by metal doping and produce lattice vacancies to enhance the number of active edges.…”

“…Nonprecious metal selenides are a promising electrocatalyst can produce a large number of active sites with remarkable hydrogen production. Among the nonnoble metal hybrid, metal selenides with a proper d‐electron configuration are considered as the promising electrocatalysts . For example, density functional theory (DFT) calculations exhibit that the transition metal selenides edges are active sites for HER.…”

Metal organic frameworks derived single atom catalysts for electrocatalytic energy conversion

“…The catalytic performance of the electrocatalysts is generally dominated by two factors, including the number of catalytically active sites and the intrinsic activity of individual active site [27]. Recent studies have demonstrated that increased number of catalytically active sites and more exposed active surface areas can be engendered by diminishing the size of catalyst particles and enhanced intrinsic properties of the metal sites can be achieved through tuning their structural configuration and electronic structure [28][29][30][31]. Downsizing the catalyst particles to atomic level offers an effective way to realize maximum utilization efficiency of metal atom and improve the intrinsic catalytic activity of the catalyst [32].…”