Perpustakaan Digital ITB

The increasing global energy demand and the environmental impact of fossil fuels have led to a growing interest in renewable energy sources such as solar energy. However, the intermittent nature of sunlight and the reliance on separate storage devices hinder the efficiency and portability of solar energy systems. Photo-rechargeable zinc-ion batteries (PRZIBs) offer a promising integrated solution by combining solar energy conversion and storage in a single device. This work reports the fabrication and evaluation of a photo-rechargeable zinc-ion battery (PRZIB) using a vanadium-based photocathode composed of NH?V?O?? (NVO) incorporated with reduced graphene oxide (rGO). The material was synthesized via a hydrothermal method and characterized by XRD, Raman spectroscopy, SEM-EDS, and UV-Vis spectroscopy. Structural and optical analysis confirmed the formation of NVO nanorods encapsulated by rGO, with a reduction in band gap energy from 2.39 eV (NVO) to 2.33 eV (NVO/rGO), indicating improved light absorption. Electrochemical performance was evaluated under dark and illuminated conditions using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge–discharge (GCD). Under illumination condition, NVO/rGO exhibited an increased specific capacity from 310 to 348 mAh g?¹, a 61% increase in CV area, and a decrease in charge transfer resistance (RCT) from 115 to 53 ?. The photo-conversion efficiency (PCE) reached 0.61%. The material also showed excellent cycling stability with 54% capacity retention after 300 cycles and full reversibility in rate capability. In comparison, pristine NVO achieved 278 mAh g?¹ (from 237 mAh g?¹), 21% CV gain, RCT reduction from 264 to 187 ?, and only 23% capacity retention. These results demonstrate the enhanced photoelectrochemical performance of NVO/rGO, highlighting its potential for future PRZIB applications.