Morphology-driven gas sensing by fabricated fractals: A review

[摘要] Fractals are intriguing structures that repeat themselves at various length scales. Interestingly, fractals can also be fabricated artificially in labs under controlled growth environments and be explored for various applications. Such fractals have a repeating unitthat spans in length from nano- to millimeter range. Fractals thus can be regarded as connectors that structurally bridge the gap between the nano- and the macroscopic worlds and have a hybrid structure of pores and repeating units. This article presents acomprehensive review on inorganic fabricated fractals (fab-fracs) synthesized in labs and employed as gas sensors across materials,morphologies, and gas analytes. The focus is to investigate the morphology-driven gas response of these fab-fracs and identify keyparameters of fractal geometry in influencing gas response. Fab-fracs with roughened microstructure, pore-network connectivity,and fractal dimension (D) less than 2 are projected to be possessing better gas sensing capabilities. Fab-fracs with these salient features will help in designing the commercial gas sensors with better performance.

[学科分类] 环境监测和分析

[关键词] adsorption sites;fabricated fractal;fractal dimension;gas sensor;morphology;pore network;recovery time;response time