Construction of Polarized Carbon–Nickel Catalytic Surfaces for Potent, Durable, and Economic Hydrogen Evolution Reactions

Abstract

Electrocatalytic hydrogen evolution reaction (HER) in alkaline solution is hindered by its sluggish kinetics toward water dissociation. Nickel-based catalysts, as low-cost and effective candidates, show great potentials to replace platinum (Pt)-based materials in the alkaline media. The main challenge regarding this type of catalysts is their relatively poor durability. In this work, we conceive and construct a charge-polarized carbon layer derived from carbon quantum dots (CQDs) on NiN nanostructure (NiN@CQDs) surfaces, which simultaneously exhibit durable and enhanced catalytic activity. The NiN@CQDs shows an overpotential of 69 mV at a current density of 10 mA cm in a 1 M KOH aqueous solution, lower than that of Pt electrode (116 mV) at the same conditions. Density functional theory (DFT) simulations reveal that NiN and interfacial oxygen polarize charge distributions between originally equal C-C bonds in CQDs. The partially negatively charged C sites become effective catalytic centers for the key water dissociation step via the formation of new C-H bond (Volmer step) and thus boost the HER activity. Furthermore, the coated carbon is also found to protect interior NiN from oxidization/hydroxylation and therefore guarantees its durability. This work provides a practical design of robust and durable HER electrocatalysts based on nonprecious metals.

Stress‐Transfer‐Induced In Situ Formation of Ultrathin Nickel Phosphide Nanosheets for Efficient Hydrogen Evolution

“…Thep resent observations of FGR-assisted growth of ultrathin Ni 2 PNSs from Ni(OH) 2 NSs can be rationalized by the stress-transfer-induced mechanism proposed in Scheme 1. During phosphorization, the residual oxygenated groups (epoxy and hydroxy groups) and lateral size of FGR contribute to interfacial bonding [24] with ultrathin 2D Ni 2 PN Ss, which facilitates stress transfer across the interface between the Ni 2 PN Ss with exposed (001) facets and FGR. Furthermore,the defects in FGR could be docking sites [25] for further stabilizing 2D Ni 2 PNSs.Inthe absence of FGR, the resultant Ni 2 Peasily forms aggregates due to random stress transfer in the interior to reach amechanical equilibrium.…”

Creating Competitive Active Sites on CNTs Walls by N‐Doping and Sublayer Co4N Encapsulating for Efficient Hydrogen Evolution Reaction

“…The carbon nanotubes wall with N doping and sublayer Co 4 N encapsulating was expect to promote the H* adsorption/desorption from the surface. In addition, the carbon nanotubes wall was also expect to reliefs the erosion of catalyst under alkaline solution electrolyte . As comparison, different catalysts Co 4 N@NF and N−CNTs were also prepared (Figure S5–S6, the preparation details of them can be seen in the Supporting Information).…”

An Efficient Acetalization Method for Biomass‐Derived Furfural with Ethanol Using γ‐Al2O3‐Supported Catalysts

“…Thus, we focused our study on developing a simple catalytic system over supported noble metals, due to the high stability and activity of Rh‐ and Pt‐supported catalysts, their solubility in alcohols, their capacity to withdraw hydrogen from alcohols, avoiding the use of extremely flammable H 2 gas, and the possibility for mild reaction conditions . Among the non‐noble metal‐based catalysts, Ni‐based catalysts are the most practical choice due to their high catalytic activity and low cost and abundance, but its poor resistant to deactivation is well known. On the other hand, the physical and chemical properties of γ‐Al 2 O 3 , such as good mechanical strength, thermal stability, controllable textural properties and low price, make γ‐Al 2 O 3 a suitable support for active metal when acid catalysts are required .…”