Rod‐Like Nanofibres Polyaniline@Expanded Graphite Based on “Achieve Two Things at One Stroke” Strategy for Supercapacitor and Photosensor Applications

Polyaniline (PANI) was formed by chemical oxidative polymerization and composited with expanded graphite (GIC) to obtain a “achieve two things at one stroke” PANI@GIC composite. In the polymerization process, rod‐shaped polyaniline was grown in situ on expanded graphite with a size of 700 to 1000 μm. The diameter of the rod‐shaped polyaniline nanofibers was 30 to 40 nm, with lengths ranging from 300 to 400 nm. Preparation of composite materials where the “one thing” refers to their application as supercapacitor. Composite materials achieving a specific capacitance of 377.3 F/g when doped with 0.49 mol/L p‐toluenesulfonic acid. Even after 1000 CV testing cycles, nearly 91.3% of the capacitance was retained. The prepared composite materials have an additional “one thing,” which refers to the application of photoactive materials. Under 1 V voltage, the photocurrent produced by P‐toluene sulfonic acid doped PANI@GIC composite under ultraviolet light and red light was 5.52 × 10 −4 A and 6.00 × 10 −5 A, respectively. PANI@GIC The composite was 9.20 times more sensitive to ultraviolet light than red light. The above results indicated that rod‐shaped nanofibrous PANI@GIC composites hold significant promise for applications in optical sensors and supercapacitors.