Large scale solar-driven hydrogen production is a crucial step toward decarbonizing society. However, the solar-to-hydrogen (STH) conversion efficiency, long-term stability, and cost-effectiveness in hydrogen evolution reaction (HER) still need to be improved. Herein, an efficient approach is demonstrated to produce low-dimensional Pt/graphene-carbon nanofibers (CNFs)-based heterostructures for bias-free, highly efficient, and durable HER. Carbon dots are used as efficient building blocks for the in situ formation of graphene along the CNFs surface. The presence of graphene enhances the electronic conductivity of CNFs to ≈3013.5 S m−1 and simultaneously supports the uniform Pt clusters growth and efficient electron transport during HER. The electrode with a low Pt loading amount (3.4 μg cm−2) exhibits a remarkable mass activity of HER in both acidic and alkaline media, which is significantly better than that of commercial Pt/C (31 μg cm−2 of Pt loading). In addition, using a luminescent solar concentrator-coupled solar cell to provide voltage, the bias-free water splitting system exhibits an STH efficiency of 0.22% upon one-sun illumination. These results are promising toward using low-dimensional heterostructured catalysts for future energy storage and conversion applications.
