A comparative study on methanol sensing performance of ZnO nanoflower and nanorod based resistive devices

A comparative study on methanol sensing performance of ZnO nanoflowers and nanorods is reported in this paper. Chemical bath deposition technique was employed to develop both the nanostructures on a sol-gel grown seed layer deposited SiO₂ substrate. 0.1(M) ZnCl₂ with 0.3(M) NH₃ solution (about 25%) used for synthesis of nanoflowers, while 0.1(M) Zn(Ac)₂ with 0.1(M) HMT was employed to escalate nanorods. Both the nanoforms, in resistive mode, were found to detect methanol with a high dynamic range of 0.5-700 ppm. Both the nanoforms offered the optimum operating temperature of 300°C with the corresponding response magnitude (RM) of 39%-92% (nanoflowers) and 54%-94.1% (nanorods) towards 0.5 ppm and 700 ppm methanol respectively. The response time of the nanorod based sensor were found to be faster than its nanoflower based counterpart. Improved methanol sensing properties of nanorods sensor (compared to nanoflower) might be attributed to the more ordered structures of nanorods.