Cation Modulation of Cobalt Sulfide Supported by Mesopore-Rich Hydrangea-Like Carbon Nanoflower for Oxygen Electrocatalysis

Abstract

Transition-metal sulfide is pursued for replacing scare platinum-group metals for oxygen electrocatalysis and is of great importance in developing low-cost, high-performance rechargeable metal–air batteries. We report herein a facile cationic-doping strategy for preparing nickel-doped cobalt sulfide embedded into a mesopore-rich hydrangea-like carbon nanoflower. Nickel cations are introduced to induce the formation of Co3+-active species and more oxygen vacancies due to higher electronegativity and smaller ionic radius, thereby strengthening the intrinsic activity for oxygen electrocatalysis. Moreover, hydrangea-like superstructure composed of interconnected carbon cages provides abundant accessible active sites and hierarchical porosity. As a result, it shows excellent catalytic performance with a superior mass activity for the oxygen reduction reaction to the state-of-the-art Pt/C catalyst and a low overpotential of 314 mV at 10 mA cm–2 for the oxygen evolution reaction. When used as an air cathode for the rechargeable Zn–air battery, it delivers a peak power density of 96.3 mW cm–2 and stably operates over 214 h. This work highlights the importance of cationic doping in strengthening the electrocatalytic performance of 3d-transition-metal chalcogenides.

Vanadium-Doping and Interface Engineering for Synergistically Enhanced Electrochemical Overall Water Splitting and Urea Electrolysis

“…By optimizing the adsorption/desorption of intermediate species, enhancing conductivity, or increasing active sites, transition metal-based catalysts, such as carbides, , nitrides, , (oxy)­hydroxides, − phosphides (phosphates), − sulfides, , selenides, , and so on, have attracted extensive attention for water electrolysis under alkaline conditions in the past few years. Among the abovementioned candidates, transition metal nitrides, especially Ni 3 N, showing metallic character and corrosion resistance, have been exploited as electrocatalysts toward HER and OER. , However, Ni 3 N has a poor adsorption toward water molecules, and therefore, the electrocatalytic water dissociation rate on it is rather slow .…”

“…13 Therefore, fabricating effective non-precious metal-based bifunctional electrocatalysts to substitute precious metals toward overall water splitting is an imperative approach. By optimizing the adsorption/desorption of intermediate species, enhancing conductivity, or increasing active sites, transition metal-based catalysts, such as carbides, 14,15 nitrides, 8,16 (oxy)hydroxides, 17−19 phosphides (phosphates), 20−22 sulfides, 23,24 selenides, 25,26 and so on, have attracted extensive attention for water electrolysis under alkaline conditions in the past few years. Among the abovementioned candidates, transition metal nitrides, especially Ni 3 N, showing metallic character and corrosion resistance, 27 have been exploited as electrocatalysts toward HER and OER.…”

Bimetallic sulfide particles incorporated in Fe/Co-based metal–organic framework ultrathin nanosheets toward boosted electrocatalysis of the oxygen evolution reaction

“…Consequently, we assume S 2− liberated by TAA first reacts with the metal (Co and Fe) ions to form sulfide nanomicrospheres, and is subsequently converted into metal sulfide particles inlaid in the MOF ultrathin nanosheets in the presence of TPA ligands. 46 Among a series of bimetallic and monometallic catalysts, the optimized CoFe-MS/MOF catalyst synthesized with a 1 : 4 Fe/Co ratio after five hours of the solvothermal reaction displayed optimal OER activity in 1 M KOH (Fig. S5b and S6-S8 †).…”

“…Consequently, we assume S 2− liberated by TAA first reacts with the metal (Co and Fe) ions to form sulfide nanomicrospheres, and is subsequently converted into metal sulfide particles inlaid in the MOF ultrathin nanosheets in the presence of TPA ligands. 46…”

Heterostructuring cobalt sulfide with highly oxophilic 1T-tungsten sulfide for durable and efficient oxygen electrocatalysis

“…), have been intensively exploited as a promising class of ORR/OER catalysts to replace expensive and scarce platinum-group metals (Pt, Ru, and Ir). 2,3 In spite of incredibly boosting the activities by means of structural, compositional, and defect engineering, 4,5 they still undergo self-oxidation under ORR/OER conditions to form (oxy)hydroxides, 6–10 accompanied by morphological changes and even structural collapse, leading to the instability of the catalytic performance.…”