In Situ Growth of Ultrathin Ni(OH)2 Nanosheets as Catalyst for Electrocatalytic Oxidation Reactions

Figure 1. (a) SEM images, (b) TEM image (Inset: SAED pattern), (c) AFM image, (d) height profiles, (e) Ni2p spectrum, and (f) O1s spectrum of the as-synthesized Ni(OH)2/NF.Figure 2. (a) LSV curves of Ni(OH)2/NF and NF in 1.0 m KOH without and with 10 mm HMF. (b) Tafel plots of Ni(OH)2/NF in 1.0 m KOH without and with 10 mm HMF (c) Cdl of Ni(OH)2/NF and NF in 1.0 m KOH (data derived from Figure S6). (d) Nyquist plots of Ni(OH)2/NF electrode in 1.0 m KOH without and with 10 mm HMF.Figure 3. (a) Chronoamperometric curves of Ni(OH)2/NF under different potentials in 1.0 m KOH solution containing 10 mm HMF. (b) Plot of HMF conversion and products yielded by Ni(OH)2/NF against reaction time in 1.0 m KOH solution containing 10 mm HMF at 1.39 V (vs. RHE). (c) Kinetic fitting curves for ECO of HMF to FDCA by Ni(OH)2/NF and NF. (d) Chronoamperometric curves and (e) FDCA yield and FE of Ni(OH)2/NF during five successive reuse cycles. (f) SEM images of Ni(OH)2/NF after reuse cycles. (g, h) Ni2p and O1s XPS spectra of Ni(OH)2/NF before and after reuse cycles, and Ni(OH)2/NF (the spectra denoted as Activated) subjected to 1.39 V (vs. RHE) for 10 min.Figure 4. (a) Kinetic fitting plots of Ni(OH)2/NF from ECO of HMFCA and DFF to FDCA in 1.0 m KOH solution containing 5 mm of HMFCA or DFF at 1.39 V vs. RHE. (b) Plots of reactant and product concentrations against reaction time for ECO of HMF catalyzed by Ni(OH)2/NF at 1.39 V (vs. RHE) potential in 25 mL 1.0 m KOH solution containing 50 mm HMF.Scheme 1. Reaction pathways for ECO of HMF to FDCA.