Air-Stable Black Phosphorus Devices for Ion Sensing.
Black phosphorus (BP) is one of the most attractive graphene analogues, and its properties make it a promising nanomaterial for chemical sensing. However, mono- and few-layer BP flakes are reported to chemically degrade rapidly upon exposure to ambient conditions. Therefore, little is known about the performance and sensing mechanism of intrinsic BP, and chemical sensing of intrinsic BP with acceptable air stability remains only theoretically explored. Here, we experimentally demonstrated the first air-stable high-performance BP sensor using ionophore coating. Ionophore-encapsulated BP demonstrated significantly improved air stability. Its performance and sensing mechanism for trace ion detection were systematically investigated. The BP sensors were able to realize multiplex ion detection with superb selectivity, and sensitive to Pb(2+) down to 1 ppb. Additionally, the time constant for ion adsorption extracted was only 5 s. The detection limit and response rate of BP were both superior to those of graphene based sensors. Moreover, heavy metal ions can be effectively detected over a wide range of concentration with BP conductance change following the Langmuir isotherm for molecules adsorption on surface. The simplicity of this ionophore-encapsulate approach provides a route for achieving air-stable intrinsic black phosphorus sensors that may stimulate further fundamental research and potential applications.
State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments, Tsinghua University , Beijing 100084, China.
Peng
P
Li
College of Information and Control Engineering, China University of Petroleum (East China) , Qingdao 266580, China.
Dongzhi
D
Zhang
College of Information and Control Engineering, China University of Petroleum (East China) , Qingdao 266580, China.
Jingjing
J
Liu
College of Information and Control Engineering, China University of Petroleum (East China) , Qingdao 266580, China.
Hongyan
H
Chang
College of Information and Control Engineering, China University of Petroleum (East China) , Qingdao 266580, China.
Yan'e
Y
Sun
College of Information and Control Engineering, China University of Petroleum (East China) , Qingdao 266580, China.
Nailiang
N
Yin
air stability; black phosphorus; chemical sensing; detection limit; ionophore