Hierarchically nanostructured materials for sustainable environmental applications

Abstract

This review presents a comprehensive overview of the hierarchical nanostructured materials with either geometry or composition complexity in environmental applications. The hierarchical nanostructures offer advantages of high surface area, synergistic interactions, and multiple functionalities toward water remediation, biosensing, environmental gas sensing and monitoring as well as catalytic gas treatment. Recent advances in synthetic strategies for various hierarchical morphologies such as hollow spheres and urchin-shaped architectures have been reviewed. In addition to the chemical synthesis, the physical mechanisms associated with the materials design and device fabrication have been discussed for each specific application. The development and application of hierarchical complex perovskite oxide nanostructures have also been introduced in photocatalytic water remediation, gas sensing, and catalytic converter. Hierarchical nanostructures will open up many possibilities for materials design and device fabrication in environmental chemistry and technology.

Magnetically separable Ag3PO4/NiFe2O4composites with enhanced photocatalytic activity

“…36 37 Surprisingly, in present case, some hierarchical APO/NFO microstructures was appeared which are formed by different combination and arrangement of dissimilar units leading to multiple functionalities and it may assists to enhance photocatalytic performance (see supporting information, Figure S3). 38,39 Such, hierarchical APO/NFO composites represent a good design that can tailor optical, mechanical and surface properties. Thus, APO/NFO composites, consisting of irregular structures with sharp corners, edges, and smooth surfaces can be fabricated without capping agents by simple precipitation method.…”

Continuous Flow Routes toward Designer Metal Nanocatalysts

“…Hierarchical systems are drawing attention in catalysis for their multicomponent and layered systems which can give rise to enhanced performance . These hierarchical systems typically require elaborate synthetic strategies.…”

Nanowire Array Structures for Photocatalytic Energy Conversion and Utilization: A Review of Design Concepts, Assembly and Integration, and Function Enabling

“…[27] Therefore, numerous strategies have been applied to lower their band gap energy such as incorporation of foreign ions, defect engineering, introducing a surface disorder layer, and forming a solid solution. Some popular strategies have been developed such as light scattering by hierarchical structures, [36] resonant light trapping/optical wave-guiding, [37] integrating with plasmonic structures, [38] and employing radiative and nonradiative energy transfer Adv. [28] Additionally, the dopants might introduce defect states within the band gap of TiO 2 , thus redshifting the active spectrum of TiO 2 .…”

“…Because of the well-controlled environment (vacuum), PVD thin films usually have low impurity and thus high quality. [7,19,36,47,76,176,177,194,195] Wang et al reported a synthesis of highly mismatched ZnO/ZnSe core/shell NW arrays on transparent conducting substrates combining CVD of ZnO NW arrays and PLD of ZnSe shell. [187] Line-of-sight deposition is another constraint, limiting the usage of PVD for substrates with complex geometry.…”