2D-MoSe2/0D-ZnO nanocomposite for improved H2S gas sensing in dry air ambience.

In this paper, we report on a micro-sensor employing two-dimensional (2D)- zero-dimensional (0D) heterostructure based on MOSe 2 /ZnO (fabricated by a novel Complementary Metal Oxide Semiconductor (CMOS) compatible microwave-irradiation-assisted solvothermal route) as a receptor. Density Functional Theory (DFT) calculations show that the heterostructure is more favorable to the adsorption of hydrogen sulfide (H 2 S) gas than the pristine 2D nanosheets. Experimentally, the device demonstrates sensitivity in the ultra-low concentration H 2 S range (i.e. 200 ppb – 6.1 ppm), and response of as high as 9.08% (200 ppb) - 186.91% (6.1 ppm) could be obtained repeatably with decent signal-to-noise ratio and response/recovery time (~600 sec). The device stands well on various sensor parameter tests including absolute response percentage, lower limit of detection (LOD), repeatability, reproducibility, hysteresis error, etc. A sensing mechanism based on Wolkentein's model is proposed to understand the detection behavior of the device. • 2D–0DMOSe 2 /ZnO nanocomposite was synthesized by two-step top-down/bottom-up approach. • Density Functional Theory (DFT) studies suggest thin nanocomposite to be selective towards H 2 S gas. • A micro-sensor based on this nanomaterial was realized based on metal IDEs inte using CMOS fabrication technique. • The device was able to detect H 2 S gas in the range of 200 ppb – 6.1 ppm. • Response of as high as 9.08–186.91% was obtained in this concentration range of this analyte. • The response and recovery time of the device was found to be in the range of ~600 seconds. [ABSTRACT FROM AUTHOR]