Accelerating Electrochemical Hydrogen Evolution by Introducing Local Proton Source in Non-Heme Iron (III) Complexes.

Fe-B alloy coupled with Fe clusters as an efficient cocatalyst for photocatalytic hydrogen evolution

Transition‐metal borides (TMBs) have recently attracted attention as excellent hydrogen evolution (HER) electrocatalysts in bulk crystalline materials. Herein, we show for the first time that VB and V3B4 have high electrocatalytic HER activity. Furthermore, we show that the HER activity (in 0.5 m H2SO4) increases with increasing boron chain condensation in vanadium borides: Using a −23 mV overpotential decrement derived from −0.296 mV (for VB at −10 mA cm−2 current density) and −0.273 mV (for V3B4) we accurately predict the overpotential of VB2 (−0.204 mV) as well as that of unstudied V2B3 (−0.250 mV) and hypothetical “V5B8” (−0.227 mV). We then derived an exponential equation that predicts the overpotentials of known and hypothetical VxBy phases containing at least a boron chain. These results provide a direct correlation between crystal structure and HER activity, thus paving the way for the design of even better electrocatalytic materials through structure–activity relationships.

Cobalt@nitrogen-doped bamboo-structured carbon nanotube to boost photocatalytic hydrogen evolution on carbon nitride

The phase of nanocrystals has a key role in the modulation of catalytic properties. Uniform and well-crystallized nickel phosphide nanocrystals with controlled phases (Ni5 P4 , Ni2 P, and Ni12 P5 ) and narrow size distributions are synthesized by a wet chemical method. The phases of the as-synthesized nickel phosphide nanocrystals are controlled by the P/Ni precursor molar ratio, heating process, and time of reaction. Rarely reported nearly monodisperse 5.6 nm Ni5 P4 nanocrystals are successfully synthesized and show superior hydrogen evolution reaction (HER) activity. Only a low overpotential of 103 mV is required to achieve the HER current of 10 mA cm-2 at a low catalyst loading of 0.12 mg cm-2 . The high HER activity is attributed to the high quality of the as-obtained Ni5 P4 nanocrystals, which have the electronic effect from the Ni5 P4 phase and also high surface area owing to the small particle size. A systematic study of the controlled synthesis of nickel phosphide nanocrystals is shown in this paper, and the HER catalytic activity is improved through the phase- and size-controlled synthesis of nanocrystals.

Highly active electrocatalysis of hydrogen evolution reaction in alkaline medium by Ni–P alloy: A capacitance-activity relationship

Three-dimensional reduced graphene oxide/carbon nanotube nanocomposites anchoring of amorphous and crystalline molybdenum sulfide: Physicochemical characteristics and electrocatalytic hydrogen evolution performances

Ru nanoclusters coupling with hierarchical phosphorus and oxygen dual-doped carbon nanotube architectures for effective hydrogen evolution reaction

Controllable synthesis of P-doped MoS2 nanopetals decorated N-doped hollow carbon spheres towards enhanced hydrogen evolution

Water electrolysis has been deemed as a simple, safe, and clean way to realize sustainable hydrogen production. However, efficacious water electrolysis for hydrogen production is highly dependent on efficient and stable electrocatalysts. Herein, we report a nanorod/nanotube array composite as highly efficient electrocatalyst toward hydrogen evolution reaction (HER) in both basic and acidic electrolytes. For the nanorod/nanotube array composite, One-dimensional RuO2 nanorods (NRs) were grown on top of WO3 nanotube arrays (NTA) through a facile solution impregnation method followed by a high-temperature calcination. The obtained RuO2 NRs/WO3 NTA demonstrates a superb electrocatalytic activity toward HER in both basic and acidic medias. To achieve a current density of 10 mA cm− 2, the required overpotentials are 33 mV in 1 M KOH and 62 mV in 0.5 M H2SO4, respectively. Furthermore, RuO2 NRs/WO3 NTA also shows an excellent long-term electrochemical stability in both the acidic and alkaline electrolytes. The electrocatalytic HER activity of RuO2 NRs/WO3 NTA is superior to most of the reported RuO2-based and Ru-based electrocatalysts, and even comparable to the state-of-the-art Pt/C catalyst. The superb HER activity of RuO2 NRs/WO3 NTA could be attributed to the structural merits including large surface area with abundant catalytically active sites, specific charge transport channel ensuring enhanced reaction kinetics and favorable bubble formation and release. The present work sheds new light on designing novel one-dimensional composite structures as highly efficient electrocatalyst for sustainable hydrogen generation. Simultaneously, the designed nanorod/nanotube array composite structure in this work is also expected to be applied in other energy conversion devices.

Microwave-pulse sugar-blowing assisted synthesis of 2D transition metal carbides for sustainable hydrogen evolution

Engineering hierarchical NiFe-layered double hydroxides derived phosphosulfide for high-efficiency hydrogen evolving electrocatalysis

MXene supported nickel-cobalt layered double hydroxide as efficient bifunctional electrocatalyst for hydrogen and oxygen evolution reactions

Construction of hydrangea-like nanosheets with transition metal phosphide/phosphate heterostructure for boosting alkaline hydrogen evolution reaction activity.

Boosting the HER electrocatalytic activity over RuCu-supported carbon nanosheets as efficient pH-independent catalysts

Doping regulation holds promise to modulate electrocatalytic performance, yet it remains largely unexplored for ferroelectric (FE) BaTiO3 (BTO). By jointly employing first-principles calculations and machine learning (ML) analysis, we examine the effect of a broad range of transition metal (TM) doping in FE BTO on the electrocatalytic hydrogen evolution reaction (HER) activity and screen out the optimal TM dopants. We unveil that some early-to-middle group TM (V, Cr, Mo, Ta, Ru)-doped BTO surfaces feature higher synthesizability, which also exhibit noticeable HER activity with |ΔGH*| < 0.2 eV owing to intermediate hydrogen adsorption strength. Among all doped surfaces, the Mo-doped one shows optimal HER activity under both out-of-plane and in-plane polarization states. We reveal an intense interplay between the hydrogen adsorption configuration and the corresponding hydrogen bonding interaction, which relies more on the TM group than the polarization state. Most importantly, we propose a physically informed descriptor of the surface oxygen p band, which better describes HER activity trends of TM-doped surfaces than conventional band descriptors.This indicates the significance of the fractional filling and bandwidth of occupied oxygen p-band states. Moreover, we establish a robust ML model that can well predict HER activity with surface-independent input parameters alone with R2 value above 0.93. From these parameters, we identify the inherent outer electron number of the TM dopant as the dominant feature, while the second ionization energy of the TM dopant and the initial polarization state show non-negligible feature importance. These findings could enlighten understanding, rational design, and accelerated discovery of element doping of FE materials for catalysis and other implications.