▎ 摘　　要

NOVELTY - Method for nano-patterning graphene, involves (a) cleaning monolayer of graphene sheet in large area on copper foil and neatly cutting using scissor in desired shape and size, (b) transferring graphene on silicon dioxide/silicon substrate by removing copper foil using copper etchant, (c) depositing metal film of silver or gold on top of graphene/silicon dioxide/silicon substrate using thermal evaporator at predefined thickness, (d) performing thermal annealing of films under vacuum to prevent oxidation at 550-600 degrees C to obtain silver or gold nanoparticles on graphene/silicon dioxide/silicon substrate, (e) annealing silver or gold nanoparticles formed samples in air ambient at 350 degrees C for selective oxidation and subsequently performing aqua-regia treatment for 30 minutes and rinsing with deionized water, (f) soaking in graphene nano-patterned sheets in hydrogen fluoride solution, rinsing with deionized water and transferring to exhalation valve membranes or layer of fabrics. USE - The method is used for nano-patterning graphene used in respiratory masks, such as N-95 and other masks for protecting human health against virus, such as corona virus and bacteria, and used in biomedical applications, such as drug delivery, bio-sensing and imaging, antibacterial material to biocompatible scaffold for cell culture due to exceptional electrical, thermal and mechanical properties with high specific surface area. ADVANTAGE - The method ensures low-cost nano-patterning of graphene to safeguard human health against virus, such as corona virus and bacteria, safeguards the human health with ongoing coronavirus crisis, researchers and companies, achieves nano-patterning of graphene on massive scale for commercial use in respiratory masks, and ensures simple and low-cost method for nano-patterning of graphene by employing the difference in reduction potentials between large area graphene and noble metal nanoparticles. DETAILED DESCRIPTION - Method for nano-patterning graphene, involves (a) cleaning monolayer of graphene sheet in large area on copper foil and neatly cutting using scissor in desired shape and size, (b) transferring graphene on silicon dioxide/silicon substrate by removing copper foil using copper etchant, (c) depositing metal film of silver or gold on top of graphene/silicon dioxide/silicon substrate using thermal evaporator for predefined thickness, (d) performing thermal annealing of films under vacuum to prevent oxidation at 550-600 degrees C to obtain silver or gold nanoparticles on graphene/silicon dioxide/silicon substrate, (e) annealing silver or gold nanoparticles formed samples in air ambient at 350 degrees C for selective oxidation and subsequently performing aqua-regia treatment for 30 minutes and rinsing with deionized water to fabricate the graphene patterns, (f) soaking graphene nano-patterned sheets in hydrogen fluoride solution, rinsing with deionized water and transferring to exhalation valve membranes or layer of fabrics.