A novel approach to impart selective response in palladium decorated reduced graphene oxide gas sensors

[Display omitted] •CRGO/TRGO is synthesized by chemical/thermal reduction of GO dispersion.•The effect of reduction method on material properties is studied.•Role of functional groups and temperature on the gas selectivity are studied.•CRGO based devices show high temperature selectivity to methane gas.•TRGO based devices show room temperature selectivity to hydrogen gas. The optimum temperature for selective gas sensing using reduced graphene oxide depends on the reducing method of graphene oxide (GO). This work reveals that chemically reduced graphene oxide (CRGO) manifests selectivity at high temperature, while thermally reduced graphene oxide (TRGO) indicates gas selectivity at room temperature (RT). Both CRGO and TRGO are synthesized from the same GO source. Palladium nanoparticles were used to increase the catalytic activity of both the sensing surfaces. Hydrogen, carbon monoxide and methane gases were used for the sensor studies. The materials have been characterized to correlate the difference in properties with the selective sensing performance.