• 文献标题:   Synthesizing N-[4-morpholinecarboximidamidoyl]carboximidamidoylated graphene oxide for fabricating high-sensitive humidity sensors
  • 文献类型:   Article
  • 作  者:   SHEN QQ, ZHANG CZ, BAI Y, NI MR
  • 作者关键词:   humidity sensor, graphene oxide, ammonia gas atmosphere, moroxydine moiety, electronic ionic conductivity
  • 出版物名称:   DIAMOND RELATED MATERIALS
  • ISSN:   0925-9635 EI 1879-0062
  • 通讯作者地址:  
  • 被引频次:   3
  • DOI:   10.1016/j.diamond.2022.109053 EA APR 2022
  • 出版年:   2022

▎ 摘  要

A lot of humidity sensors cannot accurately measure humidity of air containing NH3 gas due to reaction of NH3 gas with sensor materials. A guanidyl group is a strong hydrophilic group, moreover, guanidyl groups do not adsorb NH3 molecules via hydrogen or chemical bonds. In this paper, moroxydine moieties were grafted on surfaces of graphene oxide (GO) materials to synthesize N-[4-morpholinecarboximidamidoyl]carboximidamidoylated graphene oxide (MCGO) for fabricating humidity sensors. When RH increased from 11% to 95%, impedance value of the sensor decreased from 5.41 x 108 to 2.25 x 10(4) omega at testing frequency 100 Hz. The change of impedance was much higher than that fabricated by GO. The sensors also exhibited short response/ recovery time (2 s/20 s). Their good humidity sensing properties would be attributed to the fact that those N atoms in guanidyl groups at moroxydine moieties on the surfaces MCGO may strong interact with H atom in H2O molecules to form intermolecular hydrogen bonds and generate OH- ions to increase ionic conductivities. The impedance change of the humidity sensor at a low or high relative humidity was due to electronic or ionic conductivities, respectively.