Nanocoral-like NiSe2 modified with CeO2: A highly active and durable electrocatalyst for hydrogen evolution in alkaline solution

Se-Incorporated Porous Carbon/Ni5P4 Nanostructures for Electrocatalytic Hydrogen Evolution Reaction with Waste Heat Management

“…It is well known that charge-transfer resistance (R ct ) reveals the reaction kinetics involved in HER, and a smaller value of R ct refers to faster charge-transfer kinetics. 46 The as-prepared MF-Gr-CNTs-Se-Ni 5 P 4 shows lower values of series resistance (R s ) and R ct ∼1.69 Ω and 23.2 Ω, which are lower as compared to 1.77 Ω (R s ) and 191 Ω (R ct ) of MF-Gr-CNTs-Ni 5 P 4 , respectively (shown in Table S3). These lower values indicate the advantage of a binder-free electrocatalytic system where the Se incorporation creates smooth interfaces to facilitate faster electron/charge-transfer processes.…”

“…Moreover, to investigate the charge-transfer behavior of the electrode, electrochemical impedance spectral analysis (EIS) was carried out in 0.5 M H 2 SO 4 , and the corresponding Nyquist plots at −200 mV [vs the reversible hydrogen electrode (RHE)] were analyzed (Figure S20). It is well known that charge-transfer resistance ( R ct ) reveals the reaction kinetics involved in HER, and a smaller value of R ct refers to faster charge-transfer kinetics . The as-prepared MF-Gr-CNTs-Se-Ni 5 P 4 shows lower values of series resistance ( R s ) and R ct ∼1.69 Ω and 23.2 Ω, which are lower as compared to 1.77 Ω ( R s ) and 191 Ω ( R ct ) of MF-Gr-CNTs-Ni 5 P 4 , respectively (shown in Table S3).…”

“…The extrapolation of the Tafel slope toward the x-axis analyzes the exchange current density (Figure S19), which implies the intrinsic rates of electron transfer between electrolyte/electrode interfaces. 3,46 The exchange current density (j 0 ) values were found to be 3.80 mA/cm 2 and 1.90 mA/cm 2 for MF-Gr-CNTs-Se-Ni 5 P 4 and MF-Gr-CNTs-Ni 5 P 4 , respectively. The higher value of j 0 upon integration of selenium in the matrix reveals a faster reaction process in the forward direction owing to the rapid rate of electron transfer.…”

Atomic Layer Deposition of FeSe2, CoSe2, and NiSe2

“…For comparison purposes, the LSV and Tafel data for the state-of-the-art Pt/C electrocatalyst were also measured, as shown in Figure . To benchmark the HER performance of our ALD NiSe 2 with those NiSe 2 made by other methods (e.g., solution methods or NiO selenization ,,− ), the turnover frequency (TOF) was evaluated, as it reflects the intrinsic activity of a catalyst. − As the lower limit, the number of TOF was evaluated assuming that all of the Ni atoms in the film were catalytically active. ,, Therefore, the TOFs of the ALD NiSe 2 were calculated to be 0.109 and 0.53 s –1 at the overpotentials of 300 and 400 mV, respectively, and these numbers are quite comparable to those NiSe 2 made by other methods (Table S1), ,,− which indicates that our ALD NiSe 2 had good intrinsic HER activity. As ALD technology is renowned for uniform film coating on 3D structures with exceptional conformality, we envision that the ALD of MSe 2 will have great applications toward constructing superior 3D nanostructured electrocatalysts.…”

Ambient N2-to-NH3fixation over a CeO2nanoparticle decorated three-dimensional carbon skeleton

“…19 This unique reversible redox pair can act as an active site for adsorbed molecules or reaction intermediates. 20 Thus, CeO 2 -based nanomaterials have been extensively investigated in various catalytic reactions, such as the HER, 21 OER, 22 ORR, 23 methanol electrooxidation reaction, 24 etc. CeO 2 is active for the NRR as well, but its NH 3 production performance is impeded by its inferior conductivity.…”