Title:  Synthesis and gas-sensing characteristics of x -Fe2O3 hollow balls  Authors:  Nguyen, Duc Hoa Chu, Manh Hung, Nguyen, Van Toan Dang, Thi Thanh Le Nguyen, Van Duy Nguyen, Van Hieu  Keywords:  a-Fe2O3hollow balls;Hydrothermal;Gas sensors  Issue Date:  2016  Publisher:  ĐHQGHN    URI:  http://repository.vnu.edu.vn/handle/VNU_123/58330   The synthesis of porous metal-oxide semiconductors for gas-sensing application is attracting increased interest. In this study, a-Fe2O3 hollow balls were synthesized using an inexpensive, scalable, and template-free hydrothermal method. The gas-sensing characteristics of the semiconductors were sys-tematically investigated. Material characterization by XRD, SEM, HRTEM, and EDS reveals that single-phasea-Fe2O3hollow balls with an average diameter of 1.5 um were obtained. The hollow balls were formed by self assembly of a-Fe2O3 nanoparticles with an average diameter of 100 nm. The hollow structure and nanopores between t...