The worldwide energy structure is gradually shifting from traditional fossil fuels to new energy sources. Through the rapid development of sustainable energy, it is possible to protect the environment, tackle climate change, and improve energy security, thereby achieving sustainable development. Catalysis is the basis of the modern chemical industry, and nowadays it plays an indispensable role in sustainable energy. In this review, some sustainable energy sources including methane, biomass, hydrogen, and plastics will be introduced as alternatives to fossil fuels with emphasis on the catalyst systems employed in the generation and conversion of these sustainable energy sources. We expect such a review paper to be an appetizer in the popular topic of catalysis for sustainable energy and can inspire future research to boost the development of this interdisciplinary field.

Design and synthesis of efficient photocatalysts for hydrogen production via water splitting are of great importance from both theoretical and practical viewpoints. Many metal-based semiconductors have been explored for this purpose in recent decades. Here, for the first time, an entirely carbon-based material, bulk three-dimensionally cross-linked graphene (3DG), has been developed as a photocatalyst for hydrogen production. It exhibits a remarkable hydrogen production rate of 270 μmol·h⁻¹·g_cat⁻¹ under full-spectrum light via a hot/free electron emission mechanism. Furthermore, when combined with the widely used semiconductor TiO₂ to form a TiO₂/3DG composite, it appears to become a more efficient hydrogen production photocatalyst. The composite achieves a production rate of 1, 205 μmol·h⁻¹·g_cat⁻¹ under ultraviolet–visible (UV–vis) light and a 7.2% apparent quantum efficiency at 350 nm due to the strong synergetic effects between TiO₂ and 3DG.