Design of Metal Oxide Hollow Structures Using Soft-templating Method for High-Performance Gas Sensors

摘要: Abstract Semiconductor gas sensors based on metal oxide are widely used in a number of applications, from health and safety to energy effi-ciency emission control. Nanomaterials including nanowires, nanorods, nanoparticles have dominated the research focus thisfield owing their large surface sites that facilitate reactions. Recently, hollow structures using soft tem-plates been developed high sensing properties with large-area uniformity. Here, we provide brief overview metaloxide gas-sensing aspects template size, morphology, additives. In addition, mechanism perspectives presented. Keywords: Gas sensor, Soft-template method, Nanostructure, Hollow hemisphere, Metal decoration 1. INTRODUCTION The functional convergence Internet radio frequencyidentification, sensors, smart objects led era theInternet Things (IoT), which supplies accesses all real-world information [1]. Sensor technology is most importantfactor IoT because offer enormous amounts ofinformation for many types environment. Accordingly, varioussensors such as gas, pressure, illumination, tilt, temperature, andmotion heavily studied more preciselymeasure monitor changes environments [2]. particular,diverse applications sensor broad fields thedetection air pollutants gaseous hazards, homeland security,medical diagnosis, fuel combustion control acceleratedstudies high-performance [3-7]. should meet specialrequirements low cost, miniaturized ease ofintegration electronic circuits, performance[8]. Various optical, electrochemical, surfaceacoustic wave, semiconductor beenextensively fulfill needs [9]. particular,owing simplicity operation, flexibility inproduction, small easy integration electroniccircuits, oxides arevery promising elements [10-12]. Generally, aredetermined by three basic factors: utility factor, transducerfunction, receptor function [13]. first factor related togas diffusion (porous structure), second tothe electron transport between adjacent crystals(neck control). ability theoxide interact target gases (metal additives anddecoration). Over past decade, nanostructuressuch nanoparticles, nanotubes, nanofibers withmetal catalysts significantly improved factors,leading [14]. However, sincethese nanostructures commonly synthesized wetchemical methods or transfer methods, developing versatile andreproducible fabrication processes has remained challenge [15]. An alternative method achieving highly sensitive soft-template consisting polymermicrospheres, effective fabricating long-range orderedsubmicron various [16,17]. Inspite potential advantages, no review focused fabricated thesoft-template published best