Trends of earth‐abundant transition metal‐doped in CoSe ₂ microstructures towards improved water splitting and supercapacitor applications

Abstract

Rising high-tech innovations have brought forth alternative energy demands that in turn provide significant fillip to dig for advanced energy storage as well as conversion technologies. An efficient, low-cost, noble metal-free bifunctional catalyst for water dissociation and high energy density supercapacitor electrode can be a promising solution for a sustainably greener future. Herein, we have demonstrated a convenient strategy of defect engineering by transition metal doping for cultivating efficient active sites. The work features a highly stable (90.56% capacitance retention and ~97.86% of coulombic efficiency after 5000 cycles) asymmetric Fe doped CoSe 2 //titanium carbide (MXene) device with an energy density of 28.78 Wh/Kg at a power density of 778.6 W/Kg at a potential window of 1.5 V. Electrochemical kinetic analysis for the best-performing iron-doped cobalt selenide catalyst exposed an overpotential (ɳ 10 ) of 157 mV (Tafel slope of 112 mV/dec) and 261 mV(Tafel slope of 57 mV/dec) for hydrogen and oxygen evolution respectively. Further, the structural and electronic properties were computed using first-principle calculations to address the modifications in electronic structures. Metal doping engineers density of states near Fermi level due to charge transfer from metal to the parent CoSe 2 , further the carrier density synergistically contributes towards the enhancement in quantum capacitance, overpotential for HER and OER thereby tuning the physicochemical properties.

Synergistic effect of K+and PANI in vanadium oxide hydration by interlayer engineering boosts the ammonium ion storage

“…Problems mentioned above have arisen with other energy storage materials, and many endeavors have been put into solving them 31–35 . For example, pre‐intercalation (such as metal ions and conducting polymer) is used to stabilize layered structure and tune lattice spacing, which accelerates ion diffusion and charge‐transfer kinetics 36–42 . Specifically, Zhou et al.…”

“…[31][32][33][34][35] For example, pre-intercalation (such as metal ions and conducting polymer) is used to stabilize lay-ered structure and tune lattice spacing, which accelerates ion diffusion and charge-transfer kinetics. [36][37][38][39][40][41][42] Specifically, Zhou et al designed organic-inorganic hybrid material (ethylenediamine-vanadium, EDA-VO) for aqueous zincion batteries (ZIBs) with long lifetime and high-rate performance. The intercalation of EDA can increase interlayer spacing and improve mobility of Zn 2+ in the V-O-layered structure.…”

Machine Learning for the Expedited Screening of Hydrogen Evolution Catalysts for Transition Metal-Doped Transition Metal Dichalcogenides

“…However, because of the low-cost competitiveness due to the scarcity of platinum, research on alternative catalysts is being actively conducted [6,7]. As a result of such studies, two-dimensional (2D) transition metal dichalcogenides (TMDs) have emerged as appealing materials for promising HER electrocatalysts [8][9][10][11][12][13]. Among the TMDs receiving attention as electrocatalysts, materials based on MoS 2 have been the most extensively researched.…”