Red Carbon Dots Sensitized Ni‐Doped 2D MoS 2 Nanosheets as Electrode Materials for Visible‐Light Active Photorechargeable Supercapacitors

Developing photorechargeable electrochemical devices has become a new paradigm for addressing the efficient utilization of solar energy for renewable energy research. Herein, a unique 0D/2D heterostructure made of red carbon dots (RCDs) and Ni‐doped MoS 2 nanosheets (NMS) has been designed as electrode materials for photorechargeable supercapacitor device. Polyvinyl alcohol (PVA) has been used as a transparent matrix for the electrode, which retains the intrinsic optoelectronic properties of the composite. Photophysical properties suggest that RCDs act as efficient light‐harvesting materials as well as visible‐light photosensitizer for the device. Suitable bandgap alignment of both counterparts facilitates the photoinduced charge separation. Finally, the composite has been utilized as a visible‐light‐sensitive photorechargeable supercapacitor device. Almost 95% of enhancement in the capacitance value has been observed under light irradiation compared to the dark condition. Furthermore, wavelength dependence device performances, photo charging, and galvanostatic discharging measurements have been investigated to analyze the overall performance of the device. The device is capable of retaining its 97.25% capacity after 1000 full cycles, suggesting its excellent photostability. The plausible mechanism for photoinduced rechargeable supercapacitance properties has been discussed in detail.