▎ 摘　　要

NOVELTY - Hydrogen sensor comprises inter-metallic electrode is prepared on substrate upper layer of hydrogen sensor below set temperature control electrode, reduced-type graphene-palladium nano particles are coated on inter-digital electrode by spin coating. USE - The sensor is useful for space (claimed). ADVANTAGE - The sensor: ensures working temperature under space environment; repeats detecting ability; and improves response time to satisfy requirement of low concentration detection of hydrogen under space environment. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing the hydrogen sensor (i) preparing the inter-digital electrode on upper surface of the substrate in the hydrogen sensor, and preparing temperature control electrode under the substrate, (ii) preparing graphene oxide: respectively adding 230 ml 98% of concentrated sulfuric acid and 5 g sodium nitrate in 2 l beaker, placing into ice bath, adding 10 g 325 mesh natural graphite powder, stirring for 3 hours, adding 30 g potassium permanganate, continuously stirring for 30 minutes, restoring the reaction temperature to room temperature, and then heating and refluxing for 20 minutes, adding 1.2 l deionized water and 25 ml 30% of hydrogen peroxide, filtering the solution, washing the product using dilute hydrochloric acid aqueous solution, drying at 50 degrees C to obtain the graphene oxide, (iii) preparing reduced graphene-palladium nano particles using graphene oxide: adding 0.5-0.7 g graphene oxide and 0.1 g palladium chloride into 1 l deionized water, fully stirring the mixture for 2 minutes, adding 1-2 g sodium borohydride, dissolving in deionized water under the ice bath condition, stirring for 2.5 hours under room temperature, centrifuging and collecting precipitate, then reducing by hydrazine hydrate, centrifuging, drying at 40 degrees C to obtain the reduced graphene-palladium nano particles, where the particle size is 5 nm, the oxidation quality of graphene according to the final target thickness to be empirically adjusted, the mass of sodium borohydride for empirically adjusting according to the target particle size and (iv) coating the reduced graphene-palladium nano-particles prepared in the step (iii) on the inter-digital electrode prepared in the step (i) by spin coating. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic representation of the hydrogen sensor for space.