Effective regulation on catalytic performance of nickel–iron–vanadium layered double hydroxide for urea oxidationviasulfur incorporation

Abstract

The S-NiFeV LDH catalyst exhibits exceptional catalytic activity and stability toward the urea oxidation reaction via a sulfur-doping strategy.

Coupling NiMn-Layered Double Hydroxide Nanosheets with NiCo2S4 Arrays as a Heterostructure Catalyst to Accelerate the Urea Oxidation Reaction

“…The potential for NiCo 2 S 4 @NiMn LDH at a current density of 100 mA·cm –2 fell by 211 mV compared to the catalytic activity in 1.0 M KOH at the same current density, illustrating its excellent UOR performance. Furthermore, a response is observed for NiCo 2 S 4 @NiMn LDH in the absence of urea, deriving from the oxidation of the Ni 2+ species . To investigate the UOR reaction kinetics of the catalysts in more detail, Tafel slopes were derived from the corresponding polarization curves (Figure d).…”

“…Furthermore, a response is observed for NiCo 2 S 4 @NiMn LDH in the absence of urea, deriving from the oxidation of the Ni 2+ species. 56 To investigate the UOR reaction kinetics of the catalysts in more detail, Tafel slopes were derived from the corresponding polarization curves (Figure 4d). NiCo 2 S 4 @NiMn LDH exhibited a very low Tafel slope of 43.8 mV•dec −1 , which was much lower than that of NiCo 2 S 4 (69.2 mV•dec −1 ), NiMn LDH (95.9 mV•dec −1 ), and commercial RuO 2 (118.1 mV•dec −1 ), indicating an accelerated UOR kinetics process due to the formation of a heterogeneous interface and synergistic effects between the NiCo 2 S 4 and NiMn LDH.…”

“…In line with the LSV curves, the lowest charge transfer resistance (R ct ) for the NiCo 2 S 4 @NiMn LDH catalyst was 1.34 Ω, lower than that of NiCo 2 S 4 (1.37 Ω), NiMn LDH (1.41 Ω), commercial RuO 2 (1.79 Ω), and NF (3.96 Ω), illustrating the enhanced electron transfer efficiency at the electrode−electrolyte interface and advanced UOR kinetics of the unique heterostructure in comparison with its individual counterparts. 18,56 The ECSA is an important parameter for the estimation of the activity of a catalyst. In the present study, it was calculated based on the electrochemical C dl obtained from the CV curves produced at various scan rates in the non-Faradaic potential region (Figure S5).…”

“…NiCo 2 S 4 @NiMn LDH exhibited a very low Tafel slope of 43.8 mV·dec –1 , which was much lower than that of NiCo 2 S 4 (69.2 mV·dec –1 ), NiMn LDH (95.9 mV·dec –1 ), and commercial RuO 2 (118.1 mV·dec –1 ), indicating an accelerated UOR kinetics process due to the formation of a heterogeneous interface and synergistic effects between the NiCo 2 S 4 and NiMn LDH. , EIS tests were also conducted to investigate the UOR kinetics and electrode–electrolyte interface behavior with the fitted Nyquist plots for the samples presented in Figure e. In line with the LSV curves, the lowest charge transfer resistance ( R ct ) for the NiCo 2 S 4 @NiMn LDH catalyst was 1.34 Ω, lower than that of NiCo 2 S 4 (1.37 Ω), NiMn LDH (1.41 Ω), commercial RuO 2 (1.79 Ω), and NF (3.96 Ω), illustrating the enhanced electron transfer efficiency at the electrode–electrolyte interface and advanced UOR kinetics of the unique heterostructure in comparison with its individual counterparts. , …”

Dual cation-modified hierarchical nickel hydroxide nanosheet arrays as efficient and robust electrocatalysts for the urea oxidation reaction

“…2f, it can be divided into two distinct components, where the characteristic peaks at 530.88 eV and 531.98 eV are attributed to O-H bonds and surface-adsorbed oxygen, respectively. 28 The morphology of the prepared catalysts is also characterized by SEM and TEM. As shown by SEM in Fig.…”