Biomass Carbon Template Method Can Control The Preparation Of Cobalt-based Composite Materials And Research On Gas-sensing Properties

NH₃,as an important chemical,is a toxic gas that can easily cause an environmental pollution.To accurately determine the concentration of NH₃ in environment,the selection of gas sensitive materials for NH₃ sensors which is able to work under room temperature becomes a critical issiue.In addition,the development and utilization of biomass materials with rich resource but low utilization has also become a hot area in energy and materials science.In this study,we used the biomass materials hemp stem as a raw material to prepare a mesoporous biocarbon material?BCM?by a simple carbonization approach,and then the BCM was used as a template to synthesze Co₃O₄-based Ni-Co-O and In₂O₃-Co₃O₄composite nanomaterials,which were characterized by XRD,BET,SEM,TEM and XPS.Furthermore,we also analyzed their compositions,structures,morphologies,specific surface areas,valence states of metal atoms,and oxygen-containing species and their concentration distribution.Additionally,we assembled the sensor using the prepared nanocomposites and tested their gas sensitive abilities to NH₃,invovling selectivity,response and correlation,response time,detection limit,repeatability,and stability.The results showed that biomass materials hemp steam could be used to prepare biomass carbon materials with ordered,porous and honeycomb pore structure.Ni-Co-O and In₂O₃-Co₃O₄ composites have good gas-sensitive selectivity,high response,short response time,low detection limit,good repeatability and high stability to NH₃.The results of this study can expand the application range of biomass hemp steam and promote the comprehensive utilization of biomass resources.The synthesized porous Ni-Co-O and In₂O₃-Co₃O₄ composites can be used as the key gas sensitive materials for NH₃ sensor at room temperature,and provide a candidate gas sensitive material for the development and use of NH₃ sensor at room temperature.