Despite the Pt-catalyzed alkaline hydrogen evolution reaction (HER) progressing via oxophilic metal-hydroxide surface hybridization, maximizing Pt reactivity alongside operational stability is still unsatisfactory due to the lack of well-designed and optimized interface structures. Producing atomically flat two-dimensional Pt nanodendrites (2D-PtNDs) through our 2D nanospace-confined synthesis strategy, this study tackles the insufficient interfacial contact effect during HER catalysis by realizing an area-maximized and firmly bound lateral heterointerface with NiFe-layered double hydroxide (LDH). The well-oriented {110} crystal surface exposure of Pt promotes electronic interplay that bestows strong LDH binding. The charge-relocated interfacial bond in 2D-PtND/LDH accelerates the hydrogen generation steps and achieves nearly the highest reported Pt mass activity enhancement (∼11.2 times greater than 20 wt % Pt/C) and significantly improved long-term operational stability. This work uncovers the importance of the shape and facet of Pt to create heterointerfaces that provide catalytic synergy for efficient hydrogen production.
Next-generation electrocatalysts with smart integrated designs, maximizing the chemical cascade synergy for sustainable hydrogen production, are needed to address the urgent environmental threats, but scalable synthesis of precisely architectured nanohybrids rendering a few-nanometer interfacial controllability to augment the catalytic reactivity and operational stability is a major bottleneck. Herein, by inventing a surface-confined lateral growth of nanometer-thin and nanoporous two-dimensional (2D)-Pt on NiFe-LDH nanosheets, a highly reactive 2D−2D interfacially integrated nanoplatform is synthesized for an alkaline hydrogen evolution reaction (HER) which not only extracts high Pt-atomic utilization efficiency but also synergistically accelerates the water dissociation and hydrogen generation cascade on the colocalized Pt/M(OH) x active sites, endowing a 6.1-fold higher Pt mass activity than 20% Pt/C and also empowers a record-high HER operational stability for 50 h, due to the chemically enforced lamellar architecture. This work offers a gateway to produce active metal nanosheets tailored with a suitable active-template surface in order to invent and enforce futuristic catalysis technologies.
The development of earth‐abundant and efficient oxygen evolution reaction (OER) electrocatalysts is necessary for green hydrogen production. The preparation of efficient OER electrocatalysts requires both the adsorption sites and charge transfer on the catalyst surface to be suitably engineered. Herein, the design of an electrocatalyst is reported with significantly enhanced water oxidation performance via dual‐phase engineering, which displays a high number of adsorption sites and facile charge transfer. More importantly, a simple chemical etching process enables the formation of a highly metallic transition boride phase in conjunction with the transition metal hydroxide phase with abundant adsorption sites available for the intermediates formed in the OER. In addition, computational simulations are carried out to demonstrate the water oxidation mechanism and the real active sites in this engineered material. This research provides a new material design strategy for the preparation of high‐performance OER electrocatalysts.
Titanium dioxide (TiO) with exposed (001) facets (TiO(001)) has attractive photocatalytic properties. However, the high recombination rate of the photo-excited charge carriers on this surface often limits its application. Here, we report that a few-layered 1T-MoS coating on TiO(001) nanosheets (abbreviated as MST) can be a promising candidate that overcomes some of the challenges of TiO(001). Computational and experimental results demonstrate that MST as a photocatalyst exhibits a significantly low-charge recombination rate as well as excellent long-term durability. The synthesized MST 2D nanocomposites show a 31.9% increase in photocatalytic activity for hydrogen (H) production relative to the counterpart TiO(001). MST offers a new route for further improvement of the photocatalytic activity of TiO with exposed high energy facets.
The performance of nanocrystal (NC) catalysts could be maximized by introducing rationally designed heterointerfaces formed by the facet‐ and spatio‐specific modification with other materials of desired size and thickness. However, such heterointerfaces are limited in scope and synthetically challenging. Herein, we applied a wet chemistry method to tunably deposit Pd and Ni on the available surfaces of porous 2D−Pt nanodendrites (NDs). Using 2D silica nanoreactors to house the 2D‐PtND, an 0.5‐nm‐thick epitaxial Pd or Ni layer (e‐Pd or e‐Ni) was exclusively formed on the flat {110} surface of 2D−Pt, while a non‐epitaxial Pd or Ni layer (n‐Pd or n‐Ni) was typically deposited at the {111/100} edge in absence of nanoreactor. Notably, these differently located Pd/Pt and Ni/Pt heterointerfaces experienced distinct electronic effect to influence unequally in electrocatalytic synergy for hydrogen evolution reaction (HER). For instance, an enhanced H2 generation on the Pt{110} facet with 2D‐2D interfaced e‐Pd deposition and faster water dissociation on the edge‐located n‐Ni overpowered their facet‐located counterparts in respective HER catalysis. Therefore, a feasible assembling of the valuable heterointerfaces in the optimal 2D n‐Ni/e‐Pd/Pt catalyst overcame the sluggish alkaline HER kinetics, with a catalytic activity 7.9 times higher than that of commercial Pt/C.
Nanoscale
optimization of late transition-metal oxides for fixing
the reversible lithiation/delithiation mechanism with an in-depth
mechanistic understanding of nanocrystal (NC) conversion chemistry
is important for furthering next-generation Li-ion battery (LIB) technologies.
Herein, 1 nm-thin Ni3CoO
x
(1
nm-NCO) nanosheets synthesized through isomorphic transformation of
NiCo layered double hydroxides within a two-dimensional (2D)-SiO2 envelope are chosen. The interconversion of metal/metal-oxide
NCs under redox-switching thermal treatment, while retaining reversibility,
inspired the accomplishment of identical consequences under the harsh
operational conditions of LIB redox cycles by application of the thin-NCO-defined
2D nanospace. During charge/discharge cycles, 1 nm-NCO covered with
an in situ formed solid-electrolyte-interphase layer enables fully
reversible interconversion between the reactive NC redox pairs, as
evidenced by detailed morphological and electrochemical analyses,
thus providing high-rate capability with a specific capacity of 61.2%
at 5.0 C relative to 0.2 C, outstanding cycle stability delivering
a reversible capacity of 1169 mAh g–1, and 913 mAh
g–1 with high average Coulombic efficiency (>99.2%)
at 3.0 and 5.0 C for 1000 cycles, respectively, which has not been
achieved with other transition-metal oxides. Such a nanospace-confinement
effect on sustainability of reactive NCs to follow-up a highly reversible
conversion reaction at fast charging in LIBs is operative within a
slit-like ultrathin 2D nanogap from 1 nm-NCO only, as a relatively
thicker 7 nm-NCO anode, with accompanying larger space available,
has evidenced poor reversibility of NCs and inadequate cyclic stability
under potential high-power density LIB application.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.