title: Facile and controllable synthesis of hydroxyapatite/graphene hybrid materials with enhanced sensing performance towards ammonia.
abstract: In this work, needle-like and micro-spherical agglomerates of nanocrystalline hydroxyapatite (HA) were successfully assembled on the surface of graphene sheets with the aid of dopamine having two roles, as a template and a reductant for graphite oxide during the process of self-polymerization. The crystalline structure and micromorphology of HA can be conveniently regulated by controlling the mineralization route either with a precipitation (cHA/GR) or biomimetic methodology (bHA/GR). Both the composites exhibit improvements of ∼150% and ∼250% in sensitivity towards the sensing of ammonia at room temperature, compared with that of bare graphene. The combination of the multi-adsorption capability of HA and the electric conductivity of graphene is proposed to be the major reason for the observed enhancements. Gas sensing tests demonstrated that the HA/GR composites exhibit excellent selectivity, high sensitivity and repeatable stability towards the analytical sensing of ammonia.
authors.affiliation: State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, PR China. yonliu@csu.edu.cn.
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhang
authors.forename: Yong
authors.initials: Y
authors.lastname: Liu
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Huixia
authors.initials: H
authors.lastname: Li
authors.forename: Yanni
authors.initials: Y
authors.lastname: Tan
authors.forename: Lanlan
authors.initials: L
authors.lastname: Luo
authors.forename: Junhao
authors.initials: J
authors.lastname: Duan
authors.forename: Kaiyang
authors.initials: K
authors.lastname: Li
authors.forename: Craig E
authors.initials: CE
authors.lastname: Banks