Room-Temperature Synthesis Of Amorphous CdO Nanoflake Arrays With Superior Gas Sensing Performance

Hazardous gas is harmful to people’s health and life,hence gas sensors with high response and selectivity are highly anticipated to be developed.We employed chemical bath deposition to produce amorphous CdO nanoflake arrays（α-CdO NFAs）on FTO and interdigital electrode at room temperature.We discussed the unique advantages of α-CdO NFAs as a sensor material to detect diethyl ether by making SEM,XPS,EELS,FTIR and gas sensing tests.After that,we explored annealing treatment to fabricate polycrystalline CdO nanoflake arrays with high specific surface area which exhibited some advantages on gas sensing applicaiton.The novelties of the thesis are as below:The in-situ growth of α-CdO NFAs at room-temperature possesses several merits such as low cost,simplicity,universality for various substrate and tight contactThere are a large amount of defects on the surface of α-CdO NFAs,which are the active sites to absorb O2 and enhance the gas response.The CBD process endowsα-CdO NFAs with abundant functional groups（mainly C=O）which strongly attract DEE rather than other VOCs,thus improving gas selectivity.What’s more,the nanoflake structure is beneficial to gas diffusion,so the response is very quick.The response time is 4.5 s to 50 ppm DEE,which is the shortest time reported so far.A polycrystalline CdO NFAs was acquired with a well maintained 3D morphology by treating α-CdO NFAs with CdCl₂ solution and annealing at 350℃ for1 hour.The polycrystalline CdO NFAs exhibit high sensitivity to isopropanol（90）,and ethanol（35）.