Porous graphitic carbon nanosheets (PGCS) are synthesized by an in situ self-generating template strategy based on the carburized effect of iron with cornstalks. Cornstalks firstly coordinate with [Fe(CN)(6)](4-) ions to form the cornstalk-[Fe(CN)(6)](4-) precursor. After carbonization and removal of the catalyst, PGCS are obtained. Series experiments indicate that PGCS can only be formed when using an iron-based catalyst that can generate a carburized phase during the pyrolytic process. The unique structures of PGCS exhibit excellent capacitive performance. The PGCS-1-1100 sample (synthesized from 0.1 M [Fe(CN)(6)](4-) with a carbonization temperature of 1100 °C), which shows excellent electrochemical capacitance (up to 213 F g(-1) at 1 A g(-1)), cycling stability, and rate performance in 6 M KOH electrolyte. In the two-electrode symmetric supercapacitors, the maximum energy densities that can be achieved are as high as 9.4 and 61.3 Wh kg(-1) in aqueous and organic electrolytes, respectively. Moreover, high energy densities of 8.3 and 40.6 Wh kg(-1) are achieved at the high power density of 10.5 kW kg(-1) in aqueous and organic electrolytes, respectively. This strategy holds great promise for preparing PGCS from natural resources, including cornstalks, as advanced electrodes in supercapacitors.

The synergistic effect of WC and Pd has large benefit for ethanol electrooxidation. The small-sized Pd nanoparticles (NPs) decorated tungsten carbide on graphene (Pd-WC/GN) will be a promising anode catalyst for the direct ethanol fuel cells. The density functional theory (DFT) calculations reveal that the strong interaction exists at the interface between Pd and WC, which induces the electron transfer from WC to Pd. Fortunately, the nanoscale architecture of Pd-WC/GN has been successfully fabricated in our experiments. X-ray photoelectron spectrum further confirms the existence of electron transfer from WC to Pd in a Pd-WC/GN nanohybrid. Notably, electrochemical tests show that the Pd-WC/GN catalyst exhibits low onset potential, a large electrochemical surface area, high activity, and stability for ethanol electrooxidation in alkaline solution compared with Pd/graphene and Pd/commercial Vulcan 72R carbon catalysts. The enhancement can be attributed to the synergistic effect of Pd and WC on graphene. At the interface between Pd and WC, the electron transfer from WC to Pd leads to the increased electron densities of surface Pd, which is available for weakening adsorption of intermediate oxygen-containing species such as CO and activating catalyst. Meanwhile, the increased tungsten oxide induced by electron transfer can facilitate the effective removal of intermediate species adsorbed on the Pd surface through a bifunctional mechanism or hydrogen spillover effect.

Magnetic porous graphitic carbon (MPGC) materials were fabricated through a facile ''Solution-Solid'' route and their application as excellent adsorbents for metal ions and dye were also demonstrated. In the preparation, glucose, nickel nitrate and TEOS were selected as carbon resource, catalyst precursor and porogent, respectively. In the first step, the solution contained glucose, Ni 2+ and TEOS was treated at low temperature to impel polymerization of glucose, coordination of Ni 2+ with glucose unit and hydrolysis of TEOS simultaneous, leading to the formation of precursor (Solution process). After heating the precursors under N 2 atmosphere, the Ni-SiO 2 /carbon composites were formed (Solid process). Followed soaking with NaOH to remove SiO 2 porogent, the corresponding MPGC materials with magnetic nickel particles embedded in the graphitic carbon framework were obtained. The obtained MPGC materials show good chemical stability due to their high graphitic degree. It is noteworthy that they have exceptionally large surface areas up to 918 m 2 g À1 . The adsorption performance of MPGC are evaluated by using metal ions (Cd 2+ , Cu 2+ , Ag + , Au 3+ ) and dye (Rhodamine B, RhB) in aqueous solutions as the target. The results indicate that MPGC materials exhibit excellent adsorption capacities for metal ions (7.79 mg g À1 for copper for example), which are superior to those of activated carbons and carbon nanotubes. In addition, the materials have also exhibited good ability for adsorption of dye molecular. Notably, MPGC materials could be easily removed for reuse by an external magnet, facilitating separation and reuse of those materials as adsorbents. The adsorption kinetics for these metal ions and dye on MPGC-based adsorbents were well fitted to a pseudo-second order model.