Effect of synthesis process on the sensing performance of ZnO-rGO nanohybrid for NO 2 gas

The sensing capability of ZnO-rGO nanohybrid has been examined by means of experimental approach. ZnO-rGO synthesised by wet chemical approach (ZnO-rGO(1)) and microwave-assisted method (ZnO-rGO(2)) is drop coated onto sensor substrates and employed for detection of pollutants such as Nitrogen Dioxide (NO 2 ). The sensing film was characterised by X-ray Diffractometry, Scanning Electron Microscopy and UV–visible spectroscopy. I–V calculations were performed using keithley 2461 sourcemeter. ZnO-rGO(2) exhibited better sensitivity, almost twice the sensitivity of ZnO-rGO(1) and thrice the sensitivity of rGO, owing to the annealing effects of microwaves in addition to the fast rate of charge transfer at the heterogeneous interface of the nanohybrid. The tests for repeatability of the sensing platforms were carried out at 150 °C. ZnO-rGO(1) displayed better stability than ZnO-rGO(2). The samples have a good response and recovery along with good reproducibility.