Polyvinylpyrrolidone influenced reduced graphene oxide modified vanadium pentoxide nano rods for NO2 detection and supercapacitor application

The need for environmental monitoring and remediation drives massive research efforts to create highly efficient and advanced functional nanomaterials capable of integrating numerous functionalities with easy switching between applications. In present work we focused on hydrothermal synthesis of versatile vanadium pentoxide-reduced graphene oxide composite for both gas sensor and supercapacitor application. An improved surface area and porosity of a layered orthorhombic vanadium pentoxide/reduced graphene oxide (V₂O₅-rGO) nanorods, promotes adsorption of both target gas and electrolyte, which helps during sensing and supercapacitor applications, respectively. Effect of annealing temperature and introduction of rGO has lead into formation of vacancies and V^5 +, V⁴⁺ states. Composite shows around 130 % gas response towards 100 ppm NO₂ gas at relatively low operating temperature of 150⁰ C. Moreover, sample shows fast response and recovery (36/ 605 sec) along with good reproducibility and stability. The electrochemical measurement of composite shows 613.85 F/g specific capacitance at 5 mV/s scan rate. Further sample has good power and energy density and also good stability even after 2000 cycles. Improvement in the performance is primarily revealed due to the impact of rGO as template and more conducting electron route in composite has essentially solved some of the limitations of V₂O₅. Overall study reveals layered V₂O₅-rGO composite is ideal candidate for both sensing and supercapacitor application.