3D porous p-n α-Fe2O3/NiO heteronanostructure for ultrasensitive H2S gas sensor
Nguyễn Đức Cường, Vu Hung Sinh, Dương Tuấn Quang, Lê Thị Hòa, Vo Van Tan, Hien Duy Mai, Ki‐Joon Jeon, Phan Hong Phuoc, Nguyen Van Hieu
Abstract
The porous p-n heterojunction nanocomposite is an important sensing material to enhance gas sensing performance by creating a cooperative effect at the formed interface within p-n junctions. In this paper, the 3D porous p-n α-Fe 2 O 3 /NiO heterojunction nanocomposite was prepared by a simple hydrothermal method , which was built by connecting numerous α-Fe 2 O 3 /NiO composite nanorods , nanoparticles and nanosheets . The formation of p-n heterojunctions between two oxides and the 3D porous nanostructure made this material show excellent gas sensing performance for H 2 S gas. The response of 5α-Fe 2 O 3 /NiO heteronanostructure sensor reached 239 for 20 ppm H 2 S at the optimum operating temperature of 300 °C. Additionally, it presented quick response-recovery times (38/35 s), high selectivity, long-term stability and ultra-low detection limit of 0.038 ppb. As a result, our work offers a simple method for creating 3D porous p-n α-Fe 2 O 3 /NiO heteronanostructure as a potential sensing material for detecting hydrogen sulfide .