Since the discovery of mesoporous silica in 1990s, there have been numerous mesoporous silica-based nanomaterials developed for catalytic applications, aiming at enhanced catalytic activity and stability. Recently, there have also been considerable interests in endowing them with hierarchical porosities to overcome the diffusional limitation for those with long unimodal channels. Present processes of making mesoporous silica largely rely on chemical sources which are relatively expensive and impose environmental concerns on their processes. In this regard, it is desirable to develop hierarchical silica supports from natural minerals. Herein, we present a series of work on surface reconstruction, modification, and functionalization to produce diatomite-based catalysts with original morphology and macro-meso-micro porosities and to test their suitability as catalyst supports for both liquid- and gas-phase reactions. Two wet-chemical routes were developed to introduce mesoporosity to both amorphous and crystalline diatomites. Importantly, we have used computational modeling to affirm that the diatomite morphology can improve catalytic performance based on fluid dynamics simulations. Thus, one could obtain this type of catalysts from numerous natural diatoms that have inherently intricate morphologies and shapes in micrometer scale. In principle, such catalytic nanocomposites acting as miniaturized industrial catalysts could be employed in microfluidic reactors for process intensification.

High electrochemically active birnessite is always desirable pseudocapacitive material for supercapacitor. Here, two-dimensional (2D) compulsive malposition parallel birnessite standing on β-MnO₂ interconnected networks have been designed. Due to the restriction of β-MnO₂, compulsive malposition, slippage of MnO₆ slab, occurred in birnessite resulting in weaken binding force between birnessite slab and interlayer cations, which enhanced their electrochemical performances. Additionally, the electrical conductivity of the structure was largely promoted by the 2D charge transfer route and double-exchange mechanism in birnessite, also leading to desirable electrochemical properties. Based on the fraction of as-prepared nanostructure, the parallel birnessite exhibited good pseudocapacitance performance (660 ​F ​g⁻¹) with high rate capability. In addition, the asymmetric supercapacitor assembled by reduced graphene oxide (RGO) and as-prepared nanostructure, which respectively served as the negative and positive electrode, delivered an energy density of 33.1 ​Wh kg⁻¹ and a maximum power density of 64.0 ​kW ​kg⁻¹ with excellent cycling stability (95.8% after 10000 cycles). Finally, the study opens new avenues for synthesizing high electrochemically active birnessite structure for high-performance energy storage devices.

Layered double hydroxide (LDH), a kind of 2D layered materials, has been recognized as the promising anticorrosion materials for metal and its alloy. The microstructure, physical/chemical properties, usage in corrosion inhibition and inhibition performance of LDH have been studied separately in open literature. However, there is a lack of a complete review to summarize the status of LDH technology and the potential R&D opportunities in the field of corrosion inhibition. In addition, the challenges for LDH in corrosion inhibition of metal-based system have not been summarized systematically. Herein, we review recent advances in the rational design of LDH for corrosion inhibition of metal-based system (i.e. Mg alloy, Al alloy, steel and concrete) and high-throughput anticorrosion materials development. By evaluating the physical/chemical properties, usage in metal-based system and the corrosion inhibition mechanism of LDH, we highlight several important factors of LDH for anticorrosion performance and common features of LDH in applying different metal alloys. Finally, we provide our perspective and recommendation in this field, including high-throughput techiniques for combinatorial compositional design and rapid synthesis of anticorrosion alloys, with the goal of accelerating the development and application of LDH in corrosion inhibition of metal-based system.