Fuel cells are crucial in addressing the energy crisis and environmental challenges posed by fossil fuels. Hydrogen peroxide (H2O2) has emerged as an alternative oxidizing agent for fuel cells in airless environments, offering a convenient energy carrier that can be stored in water. Solar photocatalysis has shown promise in efficiently producing H2O2 from oxygen and water, paving the way for sustainable energy solutions. Various photocatalysts like ZnO, WO3, BiVO4, and PDI-based compounds have demonstrated high H2O2 production rates, essential for fuel cell applications. Nanometals, particularly gold nanoparticles (Au NPs), have been integrated into photocatalysts to enhance their performance by improving visible light absorption and reducing charge carrier recombination. A recent study introduced an Au/PDI composite photocatalyst that significantly improved visible light absorption and charge carrier recombination, leading to enhanced photocatalytic performance. The constructed H2O2 fuel cell utilizing this composite photocatalyst achieved remarkable results, including a high H2O2 production rate, specific capacitance, power density, and solar-to-electric energy conversion efficiency. This innovative approach represents a significant advancement in harnessing solar energy for sustainable energy production and storage.