Hydrogen sensors based on Pt-loaded WO3 sensing layers
1 Department of Optoelectronics, University of Kerala - Kariavattom, Thiruvananthapuram, Kerala 695581, India
2 Department of Physics, Govt. College Kariavattom - Thiruvananthapuram, Kerala 695581, India
3 Institute for Sensor and Information Systems (ISIS), Karlsruhe University of Applied Sciences - Moltkestr. 30, D-76133, Karlsruhe, Germany
4 Natural Science and Science Education, National Institute of Education, Nanyang Technological University Singapore 637616
5 Division of Manufacturing Engineering, School of Mechanical and Aerospace Engineering, Nanyang Technological University - Singapore 637616.
Received: 11 May 2016
Accepted: 4 July 2016
In this letter we report the enhanced sensing of platinum (Pt)-loaded tungsten oxide (WO3) sensor compared to pure WO3 sensor towards hydrogen (H2) gas at low operating temperature of 200 °C. The hydrogen sensing of pure and Pt-loaded WO3 sensors is reported at operating temperatures 200, 300 and 400 °C. The presence of Pt promotes the spillover mechanism and the dissociated H2 atoms can react with adsorbed/lattice oxygen atoms to release electrons which in turn increases the conductivity of the WO3 film. The H2 sensing mechanism of Pt-loaded WO3 sensor is investigated using micro-Raman spectroscopy. The Raman spectrum of Pt-loaded sensing layer shows a shift of symmetric stretching band from 796 to 804 cm−1 with the introduction of H2 gas.
PACS: 68.37.Hk – Scanning electron microscopy (SEM) (including EBIC) / 87.64.kp – Raman / 07.07.Df – Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing
© EPLA, 2016