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Carbon hydrogasification is the slowest reaction among all carbon-involved small-molecule transformations. Here, we demonstrate a mechanochemical method that results in both a faster reaction rate and a new synthesis route. The reaction rate was dramatically enhanced by up to 4 orders of magnitude compared to the traditional thermal method. Simultaneously, the reaction exhibited very high selectivity (99.8 % CH

Developing efficient and stable electrocatalysts is crucial for the electrochemical production of pure and clean hydrogen. For practical applications, an economical and facile method of producing catalysts for the hydrogen evolution reaction (HER) is essential. Here, we report ruthenium (Ru) nanoparticles uniformly deposited on multi-walled carbon nanotubes (MWCNTs) as an efficient HER catalyst. The catalyst exhibits the small overpotentials of 13 and 17 mV at a current density of 10 mA cm–2 in 0.5 M aq. H2SO4 and 1.0 M aq. KOH, respectively, surpassing the commercial Pt/C (16 mV and 33 mV). Moreover, the catalyst has excellent stability in both media, showing almost “zeroloss” during cycling. In a real device, the catalyst produces 15.4% more hydrogen per power consumed, and shows a higher Faradaic efficiency (92.28%) than the benchmark Pt/C (85.97%). Density functional theory calculations suggest that Ru–C bonding is the most plausible active site for the HER., To efficiently produce pure and clean H2 through electrochemical processes, an efficient and durable catalyst is essential. Here, authors report ruthenium nanoparticles anchored on multi-walled carbon nanotubes as an efficient catalyst for H2 evolution in both acidic and alkaline media.

Nitrogen-enriched two-dimensional (2D) porous polybenzimidazole (2D-HPBI) network was synthesized from the reaction between 1,2,4,5-tetraaminobenzene (TAB) and benzene-1,3,5-tricarboxylic acid (BTA) in polyphosphoric acid (PPA) medium. Interestingly, the remnant terminal groups such as amine and carboxyl groups at the periphery of 2D-HPBI were selectively stripped off by heat-treatment at 470 °C. The resultant heat-treated 2D-HPBI (HT-HPBI) displayed substantially improved electrical conductivity and thus outstanding performance as the counter electrode (CE) for the cobalt reduction reaction (CRR) in dye-sensitized solar cells (DSSCs). The charge-transfer resistance (Rct=0.51 Ω cm2) at the HT-HPBI-CE/electrolyte interface was even lower than that of Pt-CE (1.09 Ω cm2). More importantly, HT-HPBI-based CE showed near “zero” loss of electrochemical stability (1/Rct) even after 1000 potential cycles, while the 1/Rct of Pt decreased to

Platinum (Pt) nanoparticles were stably anchored on triazine-functionalized graphene nanoplatelets (TfGnPs), which were prepared by a two-step reaction starting from carboxylic acid- (CGnPs), acyl chloride- (AcGnPs) and amide-functionalized graphene nanoplatelets (AfGnPs). The resulting Pt nanoparticles on TfGnPs (Pt/TfGnPs) exhibited outstanding electrocatalytic activity with significantly enhanced stability compared with commercial Pt-based catalysts for the oxygen reduction reaction (ORR) in fuel cells (FCs) and the iodine reduction reaction (IRR) in dye-sensitized solar cells (DSSCs). For the ORR in FCs, the onset and half-wave potentials of Pt/TfGnPs under acidic conditions displayed greater positive shifts to 0.58 and 0.53 V, respectively, than those of the commercial Pt/C catalyst (0.57 and 0.52 V). For the IRR in DSSCs, Pt/TfGnPs displayed a reduced charge transfer resistance (Rct) of 0.13 Ω cm2 at the CE/electrolyte interface. This value was much lower than the Pt CE of 0.52 Ω cm2. More importantly, Pt/TfGnPs exhibited profoundly improved electrochemical stability in both the ORR and IRR compared to the Pt-based catalysts. The combination of extraordinarily high electrocatalytic activity with stability could be attributed to the high specific surface area (963.0 m2 g−1) and the triazine units of the TfGnPs, respectively, which provided more active sites and stably anchored the Pt nanoparticles.

One feasible alternative to Pt catalyst in dye-sensitized solar cells (DSSCs) is metalloid tellurium (Te)-doped graphene nanoplatelets (TeGnPs). These were prepared by ball-milling graphite in the presence of Te crystals. Introduction of Te at the edges of TeGnPs was confirmed with various analytical techniques including time of flight secondary ion mass spectrometry (TOF-SIMS). The resultant TeGnPs are herein evaluated as counter electrode (CE) materials for the cobalt reduction reaction (CRR) in DSSCs. TeGnP-CE exhibits much lower charge transfer resistance ( R ct =0.15 Ω cm 2 ) than that ( R ct =1.77 Ω cm 2 ) of Pt-CE. More importantly, TeGnP-CE displays an extreme electrochemical stability for the Co(bpy) 3 2+/3+ (bpy=2,2'-bipyridine) redox couple even after 1000 potential cycles. The SM315-based DSSC fabricated with TeGnP-CE shows a better power conversion efficiency (PCE=11.58%) than that with Pt-CE (11.03%), suggesting that TeGnP-CE could be one of the best alternatives to Pt-CE in DSSCs.

Developing clean and renewable energy resources has become one of the world's most important challenges, given the double burden of energy scarcity and environmental pollution. For sustainable energy conversion and storage, efficient electrocatalysts play a pivotal role in important energy‐related reactions, including oxygen reduction, oxygen evolution, and hydrogen evolution. To satisfy practical requirements, the catalysts need to demonstrate high performance, durability, and acceptable cost. These are primary considerations when designing and preparing various new electrocatalysts. Among the research programs being actively conducted around the world, some promising recent results suggest strong potential alternatives to current expensive noble metal‐based catalysts. This review summarizes recent technical advances in the preparation of efficient electrocatalysts.

A scalable and low-cost production of graphene nanoplatelets (GnPs) is one of the most important challenges for their commercialization. A simple mechanochemical reaction has been developed and applied to prepare various edge-functionalized GnPs (EFGnPs). EFGnPs can be produced in a simple and ecofriendly manner by ball milling of graphite with target substances (X = nonmetals, halogens, semimetals, or metalloids). The unique feature of this method is its use of kinetic energy, which can generate active carbon species by unzipping of graphitic CC bonds in dry conditions (no solvent). The active carbon species efficiently pick up X substance(s), leading to the formation of graphitic CX bonds along the broken edges and the delamination of graphitic layers into EFGnPs. Unlike graphene oxide (GO) and reduced GO (rGO), the preparation of EFGnPs does not involve toxic chemicals, such as corrosive acids and toxic reducing agents. Furthermore, the prepared EFGnPs preserve high crystallinity in the basal area due to their edge-selective functionalization. Considering the available edge X groups that can be selectively employed, the potential applications of EFGnPs are unlimited. In this context, the synthesis, characterizations, and applications of EFGnPs, specifically, as metal-free carbon-based electrocatalysts for dye-sensitized solar cells (DSSCs) in both cobalt and iodine electrolytes are reviewed.