Tailored Catalytic Nanoframes from Metal–Organic Frameworks by Anisotropic Surface Modification and Etching for the Hydrogen Evolution Reaction

Abstract

A facile anisotropic surface modification and etching strategy is presented for the synthesis of hollow structured ZIF‐67 nanoframes. The strategy uses structural and compositional distinctions between each crystallographic facet of truncated rhombic dodecahedrons ZIF‐67 (tZIF‐67 RDs) and the moderate coordinating and etching effects of cyanuric acid (CA). The CA can anisotropically modify and protect the {110} facets from etching, causing the six {100} facets be selectively etched via an inside‐out manner, and finally forming the hollow nanoframes. The surface‐modified hollow tZIF‐67 RDs can be facet‐selectively etched by metal salts in an outside‐in manner to give metal‐doped tZIF‐67 nanoframes. After calcination, the metal‐tZIF‐67 hybrids are converted into metal‐Co alloy/C composite catalysts with hollow nanoframed structures. The PtCo/C catalyst with only 5.9 wt % Pt exhibits high catalytic activities and stabilities in the hydrogen evolution reaction (HER) in acidic solutions.

Wet‐Chemistry: A Useful Tool for Deriving Metal–Organic Frameworks toward Supercapacitors and Secondary Batteries

“…For example, Cai et al intentionally synthesized ZIF hollow nanoframes via the strategy of facet-selective surface protection and chemical etching. [65] The template precursors, namely truncated ZIF-67 rhombic dodecahedrons, bear two types of crystal facets exposed that are {100} and {110}. In comparison with that of {100} facet, the sparsely packed open structure of {110} facet allows the coordinated cobalt ions accessible by foreign molecules with suitable size (Figure 1a).…”

“…Typically, the growth of MOF precursors involves three steps of nucleation, seed formation, and crystal growth. During synthesis, defects are formed [65] Copyright 2021, Wiley-VCH. d,e) Etching of TRD ZIF-8 into hexapod ZIF-8 and the corresponding contour evolution observed by time-lapse optical microscopy.…”

Nanoporous ultra-high-entropy alloys containing fourteen elements for water splitting electrocatalysis

“…S14 † ). 38,39 The calculated C dl of np-UHEA14 was 9.0 mF cm −2 , which was larger than those of np-UHEA13 (6.7 mF cm −2 ) and np-UHEA12 (4.7 mF cm −2 ), revealing that a larger proportion of active sites were available in the np-UHEA14 catalyst (Fig. S14(d) † ).…”

Rational Design and Growth of MOF‐on‐MOF Heterostructures

“…[ 9–14 ] Therefore, the rational design and fabrication of different MOF structures are of great significance, as MOFs have been an emerging and fascinating subclass of crystalline porous inorganic‐organic hybrids. [ 15–18 ] In this context, MOFs and their derivatives have been well studied by many researchers in different applications, such as gas storage and separation, [ 19–21 ] gas removal, [ 22,23 ] pollutant removal, [ 24–27 ] heterogeneous catalysis, [ 28–30 ] drug delivery, [ 31–33 ] sensing, [ 34–37 ] and energy storage and conversion. [ 38–42 ] In 1995, the Yaghi research group first proposed the scientific concept of the MOF.…”