Functionalization of Hollow Nanomaterials for Catalytic Applications: Nanoreactor Construction

Abstract

Hollow nanomaterials have attracted a broad interest in multidisciplinary research due to their unique structure and preeminent properties. Owing to the high specific surface area, well-defined active site, delimited void space, and tunable mass transfer rate, hollow nanostructures can serve as excellent catalysts, supports, and reactors for a variety of catalytic applications, including photocatalysis, electrocatalysis, heterogeneous catalysis, homogeneous catalysis, etc. Based on state-of-the-art synthetic methods and characterization techniques, researchers focus on the purposeful functionalization of hollow nanomaterials for catalytic mechanism studies and intricate catalytic reactions. Herein, an overview of current reports with respect to the catalysis of functionalized hollow nanomaterials is given, and they are classified into five types of versatile strategies with a top-down perspective, including textual and composition modification, encapsulation, multishelled construction, anchored single atomic site, and surface molecular engineering. In the detailed case studies, the design and construction of hierarchical hollow catalysts are discussed. Moreover, since hollow structure offers more than two types of spatial-delimited sites, complicated catalytic reactions are elaborated. In summary, functionalized hollow nanomaterials provide an ideal model for the rational design and development of efficient catalysts.

Cross‐Linked Surface Engineering to Improve Iron Porphyrin Catalytic Activity

“…As such, using of MOFs as a hard‐template is a straightforward and universal method for obtaining hollow nanostructures and, the hollow nanostructures can be acted as a skeleton for heterogeneous catalysts to catalyze specific reactions. [ 11 ] Distinctively, construction of quasi‐two‐dimensional (QTD) porous solid based MOFs film is one of most efficiency strategy to endow materials with desired surface properties (e.g., permeability, adhesion, erosion, elasticity, and photoelectric properties) and large‐scale contactable active sites, but still a challenge until now. Suboptimal controllability and complexity of synthesis, finiteness of available MOFs resources as well as poor stability are the main obstacles hinder QTD film based material's application.…”

Designed Formation of Double‐Shelled Ni–Fe Layered‐Double‐Hydroxide Nanocages for Efficient Oxygen Evolution Reaction

“…[ 25–27 ] Compared with single‐shelled hollow structures, hollow catalysts with the multi‐shelled feature exhibit apparent superiorities for electrocatalysis. [ 28–30 ] To be more specific, multi‐shells provide larger surface area and better utilization of the inner space. Moreover, the interlayers can support each other for enhanced mechanical stability.…”

Hollow Covalent Triazine Frameworks with Variable Shell Thickness and Morphology

“…Most of the researches on CTFs are focused on the exploration of their synthetic methods, structural designs, and different applications in various fields, such as gas capture and storage, energy storage, and catalysis . In addition, controlling the nanoscale morphology of materials is an important research target in material science due to the merits originated from quantum effects in a variety of applications . However, to the best of our knowledge, most of the reported CTFs show irregular morphologies, mainly due to the lack of suitable mild synthetic methods.…”