Improved Cl2 sensing characteristics of reduced graphene oxide when decorated with copper phthalocyanine nanoflowers

Abstract

A novel gas sensing platform involving a hybrid of reduced graphene oxide (rGO) sheets with unsubstituted copper phthalocyanine (CuPc) nanoflowers has been explored as a room temperature ppb level chemiresistive chlorine (Cl₂) sensor with a detection limit as low as 1.97 ppb. The synthesized CuPc/rGO hybrid was characterized by TEM, XRD, FTIR, Raman and UV-Vis spectroscopic and TGA techniques. Improved Cl₂ sensing characteristics of rGO on decorating with CuPc nanoflowers is attributed to the synergetic effect of the presence of more Cl₂ specific interaction sites in CuPc molecules with nanoflower type morphology along with the conducting network produced by high surface area rGO sheets. A plausible gas sensing mechanism based on Raman and electrochemical impedance spectroscopy (EIS) studies has been proposed.