For the carbon-based catalyst to be active and stable, especially in harsh electrochemical environments, the key is to decrease the concentration of defects and raise the degree of graphitization of the carbon support. Herein, we develop a highly graphitized graphene foam with multiplicated structure to fabricate self-supporting Pt-based catalysts for efficient and stable HER performance. Graphene foam (GO-2850) is obtained through an ultra-high temperature treatment at 2850 ℃, with perfect graphene structure and extremely low defect, ensuring high electrical conductivity and corrosion resistance. Additionally, its multiplicated structure provides an inherently favorable environment for the dispersion of Pt nanoparticles (Pt NPs) and offers abundant channels for electrolyte infiltration during the catalytic process. As a result, the as-prepared Pt/GO-2850 is far active and stable than the Pt NPs supported on commercial carbon paper (Pt/CP) counterpart toward catalyzing HER, exhibiting an outstanding activity and long-term durability (300 h @ 10 mA cm^-2) in acidic/alkaline/seawater electrolytes. This can be attributed to the stronger interaction between the lower-defect GO-2850 substrate and Pt, as evidenced by characterization and theoretical calculations. This work extends further insight into the design self-supporting catalysts of high activity and stability with promising prominent application toward green energy devices.

Conventional glassy carbon electrodes (GCE) cannot meet the requirements of future electrodes for wider use due to low conductivity, high cost, non-portability, and lack of flexibility. Therefore, cost-effective and wearable electrode enabling rapid and versatile molecule detection is becoming important, especially with the ever-increasing demand for health monitoring and point-of-care diagnosis. Graphene is considered as an ideal electrode due to its excellent physicochemical properties. Here, we prepare graphene film with ultra-high conductivity and customize the 3-electrode system via a facile and highly controllable laser engraving approach. Benefiting from the ultra-high conductivity (5.65 × 10⁵ S·m⁻¹), the 3-electrode system can be used as multifunctional electrode for direct detection of dopamine (DA) and enzyme-based detection of glucose without further metal deposition. The dynamic ranges from 1–200 μM to 0.5–8.0 mM were observed for DA and glucose, respectively, with a limit of detection (LOD) of 0.6 μM and 0.41 mM. Overall, the excellent target detection capability caused by the ultra-high conductivity and ease modification of graphene films, together with their superb mechanical properties and ease of mass-produced, provides clear potential not only for replacing GCE for various electrochemical studies but also for the development of portable and high-performance electrochemical wearable medical devices.