Under the double pressure of both the energy crisis and environmental pollution, the exploitation and utilization of hydrogen, a clean and renewable power resource, has become an important trend in the development of sustainable energy-production and energy-consumption systems. In this regard, the electrocatalytic hydrogen evolution reaction (HER) provides an efficient and clean pathway for the mass production of hydrogen fuel and has motivated the design and construction of highly active HER electrocatalysts of an acceptable cost. In particular, graphene-based electrocatalysts commonly exhibit an enhanced HER performance owing to their distinctive structural merits, including a large surface area, high electrical conductivity, and good chemical stability. Considering the rapidly growing research enthusiasm for this topic over the last several years, herein, a panoramic review of recent advances in graphene-based electrocatalysts is presented, covering various advanced synthetic strategies, microstructural characterizations, and the applications of such materials in HER electrocatalysis. Lastly, future perspectives on the challenges and opportunities awaiting this emerging field are proposed and discussed.

The oxidation of CO molecules on Al-embedded graphene has been investigated by using the first principles calculations. Both Eley-Rideal (ER) and Langmuir-Hinshelwood (LH) oxidation mechanisms are considered. In the ER mechanism, an O 2 molecule is first adsorbed and activated on Al-embedded graphene before a CO molecule approaches, the energy barrier for the primary step (CO + O 2 / OOCO) is 0.79 eV. In the LH mechanism, O 2 and CO molecules are firstly co-adsorbed on Al-embedded graphene, the energy barrier for the rate limiting step (CO + O 2 / OOCO) is only 0.32 eV, much lower than that of ER mechanism, which indicates that LH mechanism is more favourable for CO oxidation on Al-embedded graphene. Hirshfeld charge analysis shows that the embedded Al atom would modify the charge distributions of co-adsorbed O 2 and CO molecules. The charge transfer from O 2 to CO molecule through the embedded Al atom plays an important role for the CO oxidation along the LH mechanism.Our result shows that the low cost Al-embedded graphene is an efficient catalyst for CO oxidation at room temperature.