Hetero MOF‐on‐MOF‐derived carbon nanotube interconnected nitrogen‐doped carbon‐encapsulated FeNi/FeF₂ for efficient oxygen evolution reaction

Abstract

Heterostructures derived from metal-organic frameworks (MOFs) with multicomponent synergism are significant in the energy conversion and catalysis reactions. Herein, we demonstrated such an efficient catalyst with the structure of self-catalyzed nitrogen-doped carbon nanotube interconnected FeNi/FeF 2 derived from hetero-zeolite imidazolate frameworks 8 (ZIF-8) on Fe 2 Ni MIL (MIL represents Materials of Institut Lavoisier) for oxygen evolution reaction.The obtained catalyst showed efficient synergism of the multicomponents, high polarity, more active sites exposure, increased intrinsic activity, and improved conductivity and stability by a carbon interconnected and confined structure as revealed by the spectroscopic analysis and electrochemical measurements. It required an overpotential of only ca. 240 mV (no iR correction) to reach the current density of 10 mA cm −2 in a KOH solution when loaded on an inert glass carbon electrode, much better than similar kinds of catalysts. The improved catalytic performance can be well correlated to the structural transformation step by step from different MOFs to their derivatives by subsequent carbonation and fluorination. Because of the above-mentioned structural advantages, good catalysis performance of high activity and stability, faster catalytic kinetics, and facile active phase formation were observed compared to those of other similar materials. This work offers a new platform of derivatives from hetero MOF-on-MOF for catalysis reactions.

Hierarchical Hollow CoWO4–Co(OH)2 Heterostructured Nanoboxes Enabling Efficient Water Oxidation Electrocatalysis

“…In contrast, the required overpotentials were 342 and 442 mV for Co­(OH) 2 to achieve 10 and 50 mA cm –2 , respectively, confirming the superior OER activity. In addition, CoWO 4 –Co­(OH) 2 -1 and CoWO 4 –Co­(OH) 2 -3 nanoboxes can also exhibit remarkably superior OER activity with low overpotentials as compared to the Co­(OH) 2 nanoboxes and commercial RuO 2 electrocatalysts (Figure S6) due to the strong synergistic effect between different components and distinct structural advantages. , Moreover, the Tafel plots of these four electrocatalysts that derived from LSV polarization curves are also shown in Figure c. As seen, the Tafel slope of CoWO 4 –Co­(OH) 2 -2 was as small as of 70.6 mV dec –1 , which was much smaller than those of Co­(OH) 2 (117.0 mV dec –1 ), CoWO 4 –Co­(OH) 2 -1 (89.2 mV dec –1 ), and CoWO 4 –Co­(OH) 2 -3 (83.5 mV dec –1 ), indicating that the coupling of CoWO 4 can greatly accelerate the reaction kinetics.…”

“…In addition, CoWO 4 − Co(OH) 2 -1 and CoWO 4 −Co(OH) 2 -3 nanoboxes can also exhibit remarkably superior OER activity with low overpotentials as compared to the Co(OH) 2 nanoboxes and commercial RuO 2 electrocatalysts (Figure S6) due to the strong synergistic effect between different components and distinct structural advantages. 39,40 Moreover, the Tafel plots of these four electrocatalysts that derived from LSV polarization curves are also shown in Figure 4c. As seen, the Tafel slope of 4e).…”

Cation–Anion Dual Doping Modifying Electronic Structure of Hollow CoP Nanoboxes for Enhanced Water Oxidation Electrocatalysis

“…Substituting Ir- and Ru-based materials with cost-effective transition metal compounds (TMCs) for oxygen evolution reaction (OER) is critical since the four-electron-transfer OER is a rate-determining process for water electrolysis. − In particular, intensive endeavors have been devoted to the exploration of cheaper TMCs. − Among them, transition metal phosphides, especially for CoP, have been widely investigated for boosting electrocatalytic OER owing to its excellent electrocatalytic activity. − However, the high electronegativity of P has endowed CoP with low conductivity. As is well known to all, the electron transfer capability plays a crucial role in affecting the catalytic properties of catalysts, where a high conductivity will accelerate charge transfer to boost redox reaction .…”

A high-efficiency zirconium-based single-atom catalyst for the transformation of biomass-derived 5 hydroxymethylfurfural to 2,5-bis(hydroxymethyl)furan with nearly 100% selectivity

“…As is well-known, single-atom catalysts (SACs) are the emerging research frontier in the field of heterogeneous catalysis. [65][66][67] Due to a series of unique features, such as tunable metal-coordination configurations, obvious quantumsize effects, high atom-utilization efficiencies and strong atom-substrate interactions, 68 they show splendid performance in many catalytic reactions, such as the hydrogen evolution reaction, [69][70][71] oxygen evolution reaction [72][73][74] and carbon dioxide reduction. [75][76][77] Unfortunately, SACs have been rarely employed for the TH of HMF to BHMF.…”