Ping Cai

A RhNiP/rGO hybrid for efficient catalytic hydrogen generation from an alkaline solution of hydrazine

Transition metal phosphide based hybrids (RhNiP/rGO) with different phosphorus contents have been successfully synthesized via a facile one-pot co-reduction route. Thanks to the synergistic electronic effect between Rh, Ni, and P, the as-synthesized RhNiP/rGO hybrid exhibits superior catalytic activity toward hydrogen generation from an alkaline solution of hydrazine.

Nitrogen-doped graphene hydrogel-supported NiPt-CeO x nanocomposites and their superior catalysis for hydrogen generation from hydrazine at room temperature

The safe and efficient storage and release of hydrogen is one of the key technological challenges for the fuel cell-based hydrogen economy. Hydrazine monohydrate has attracted considerable attention as a safe and convent chemical hydrogen-storage material. Herein, we report the facile synthesis of NiPt-CeOx nanocomposites supported by three-dimensional nitrogen-doped graphene hydrogels (NGHs) via a simple one-step co-reduction synthesis method. These catalysts were composition-dependent for hydrogen generation from an alkaline solution of hydrazine. (Ni5Pt5)1-(CeOx)0.3/NGH exhibited the highest catalytic activity, with 100% hydrogen selectivity and turnover frequencies of 408 h–1 at 298 K and 3,064 h–1 at 323 K. These superior catalytic performances are attributed to the electronic structure of the NiPt centers, which was modified by the electron interaction between NiPt and CeOx and the strong metal–support interaction between NiPt-CeOx and the NGH.

NiPt Nanocatalysts Supported on Boron and Nitrogen Co-Doped Graphene for Superior Hydrazine Dehydrogenation and Methanol Oxidation

Boron and nitrogen co‐doped graphene (BNG) with negligible covalent boron–nitride (BN) bonding, and high boron and pyridinic nitrogen contents has been synthesized by a two‐step method using boron–carbon–nitride (BCN) as the boron and nitrogen sources. The use of the BCN precursor is the key for preparing BNG, while annealing reduced graphene oxide, urea, and boric acid in a one‐step method results in separated domains of larger amounts of covalent BN in the graphene networks (s‐BNG). The resulting BNGs are further used to anchor NiPt nanoparticles (NPs) with good dispersion. Consequently, Ni3Pt7/BNG‐1000 exhibits the highest catalytic activity toward hydrazine dehydrogenation at room temperature, with the turnover frequency of 199.4 h−1. Furthermore, as evidence of its multifunctionality, Ni3Pt7/BNG‐1000 is further employed for electrocatalytic methanol oxidation.

Ultrasmall Ir nanoparticles for efficient acidic electrochemical water splitting

The exploration of highly active catalysts with superior stability for overall water splitting has received considerable attention. Although intensive efforts have been made to design numerous electrocatalysts for water splitting in alkaline media, only a few electrocatalysts have been developed for proton exchange membrane (PEM)-based electrolyzers in acidic media. Herein, we report a colloidal synthesis of well dispersed ultrasmall Ir NPs with narrow size distribution, of superior catalytic activity and stability toward HER and OER in acidic media. When further used as both an anode and a cathode for acidic overall water splitting, the as-synthesized monodisperse Ir NPs yield a current density of 10 mA cm−2 at 1.58 V with long-term stability.

Colloidal synthesis of iridium-iron nanoparticles for electrocatalytic oxygen evolution

The design of high-performance electrocatalysts for oxygen evolution reactions (OER) in acidic condition is highly desirable for the development of the proton exchange membrane (PEM)-based water electrolyzer. Herein, we report the colloidal synthesis of iridium-iron alloy nanoparticles with an average diameter of 2.4 nm. The as-synthesized IrFe alloy produces a current density of 10 mA cm−2 in acidic and alkaline conditions at overpotentials of 278 and 286 mV, respectively.