14 research outputs found
Facile Synthesis of Graphene/Metal Nanoparticle Composites via Self-Catalysis Reduction at Room Temperature
Graphene/metal
nanoparticle (NP) composites have attracted great interest for various
applications as catalysts, electrodes, sensors, etc., due to their
unique structures and extraordinary properties. A facile synthesis
of graphene/metal NP composites with good control of size and morphology
of metal NPs is critical to the practical applications. A simple method
to synthesize graphene/metal NPs under a controllable manner via a
self-catalysis reduction at room temperature has been developed in
this paper. At first, metal NPs with desirable size and morphology
were decorated on GO and then used as catalyst to accelerate the hydrolysis
reaction of NaBH<sub>4</sub> to reduce the graphene oxide. Compared
to the existing methods, the method reported here features several
advantages in which graphene/metal NPs are prepared without using
toxic and explosive reductant, such as hydrazine or its derivatives,
making it environmentally benign, and the reaction can be processed
at room temperature with high efficiency and in a large range of pH
values. The approach has been demonstrated to successfully synthesize
graphene composites with various metal NPs in large quantity, which
opens up a novel and simple way to prepare large-scale graphene/metal
or graphene/metal oxide composites under mild conditions for practical
applications. For example, graphene/AuNP composites synthesized by
the method show excellent catalytic capability
X‑ray Insights into Formation of −O Functional Groups on MXenes: Two-Step Dehydrogenation of Adsorbed Water
Engineered MXene surfaces with more −O functional
groups
are feasible for realizing higher energy density due to their higher
theoretical capacitance. However, there have been only a few explorations
of this regulation mechanism. Investigating the formation source and
mechanism is conducive to expanding the adjustment method from the
top-down perspective. Herein, for the first time, the formation dynamics
of −O functional groups on Mo2CTx are discovered as a two-step dehydrogenation of adsorbed water
through in situ near-ambient-pressure X-ray photoelectron spectroscopy,
further confirmed by ab initio molecular dynamics simulations. From
this, the controllable substitution of −F functional groups
with −O functional groups is achieved on Mo2CTx during electrochemical cycling in an aqueous
electrolyte. The obtained Mo2CTx with rich −O groups exhibits a high capacitance of 163.2
F g –1 at 50 mV s –1, together
with excellent stability. These results offer new insights toward
engineering surface functional groups of MXenes for many specific
applications
X‑ray Insights into Formation of −O Functional Groups on MXenes: Two-Step Dehydrogenation of Adsorbed Water
Engineered MXene surfaces with more −O functional
groups
are feasible for realizing higher energy density due to their higher
theoretical capacitance. However, there have been only a few explorations
of this regulation mechanism. Investigating the formation source and
mechanism is conducive to expanding the adjustment method from the
top-down perspective. Herein, for the first time, the formation dynamics
of −O functional groups on Mo2CTx are discovered as a two-step dehydrogenation of adsorbed water
through in situ near-ambient-pressure X-ray photoelectron spectroscopy,
further confirmed by ab initio molecular dynamics simulations. From
this, the controllable substitution of −F functional groups
with −O functional groups is achieved on Mo2CTx during electrochemical cycling in an aqueous
electrolyte. The obtained Mo2CTx with rich −O groups exhibits a high capacitance of 163.2
F g –1 at 50 mV s –1, together
with excellent stability. These results offer new insights toward
engineering surface functional groups of MXenes for many specific
applications
Liquid-Metal-Based Super-Stretchable and Structure-Designable Triboelectric Nanogenerator for Wearable Electronics
The
rapid advancement of intelligent wearable electronics imposes
the emergent requirement for power sources that are deformable, compliant,
and stretchable. Power sources with these characteristics are difficult
and challenging to achieve. The use of liquid metals as electrodes
may provide a viable strategy to produce such power sources. In this
work, we propose a liquid-metal-based triboelectric nanogenerator
(LM-TENG) by employing Galinstan as the electrode and silicone rubber
as the triboelectric and encapsulation layer. The small Young’s
modulus of the liquid metal ensures the electrode remains continuously
conductive under deformations, stretching to a strain as large as
∼300%. The surface oxide layer of Galinstan effectively prevents
the liquid Galinstan electrode from further oxidization and permeation
into silicone rubber, yielding outstanding device stability. Operating
in the single-electrode mode at 3 Hz, the LM-TENG with an area of
6 × 3 cm<sup>2</sup> produces an open-circuit voltage of 354.5
V, transferred short-circuit charge of 123.2 nC, short-circuit current
of 15.6 μA, and average power density of 8.43 mW/m<sup>2</sup>, which represent outstanding performance values for TENGs. Further,
the LM-TENG maintains stable performance under various deformations,
such as stretching, folding, and twisting. LM-TENGs in different forms,
such as bulk-shaped, bracelet-like, and textile-like, are all able
to harvest mechanical energy from human walking, arm shaking, or hand
patting to sustainably drive wearable electronic devices
Monolayer Thiol Engineered Covalent Interface toward Stable Zinc Metal Anode
Interface engineering of zinc metal anodes is a promising
remedy
to relieve their inferior stability caused by dendrite growth and
side reactions. Nevertheless, the low affinity and additional weight
of the protective coating remain obstacles to their further implementation.
Here, aroused by DFT simulation, self-assembled monolayers (SAMs)
are selectively constructed to enhance the stability of zinc metal
anodes in dilute aqueous electrolytes. It is found that the monolayer
thiol molecules relatively prefer to selectively graft onto the unstable
zinc crystal facets through strong Zn–S chemical interactions
to engineer a covalent interface, enabling the uniform deposition
of Zn2+ onto (002) crystal facets. Therefore, dendrite-free
anodes with suppressed side reactions can be achieved, proven by in
situ optical visualization and differential electrochemical mass spectrometry
(DEMS). In particular, the thiol endows the symmetric cells with a
4000 h ultrastable plating/stripping at a specific current density
of 1.0 mA cm–2, much superior to those of bare zinc
anodes. Additionally, the full battery of modified anodes enables
stable cycling of 87.2% capacity retention after 3300 cycles. By selectively
capping unstable crystal facets with inert molecules, this work provides
a promising design strategy at the molecular level for stable metal
anodes
Liquid-Metal-Based Super-Stretchable and Structure-Designable Triboelectric Nanogenerator for Wearable Electronics
The
rapid advancement of intelligent wearable electronics imposes
the emergent requirement for power sources that are deformable, compliant,
and stretchable. Power sources with these characteristics are difficult
and challenging to achieve. The use of liquid metals as electrodes
may provide a viable strategy to produce such power sources. In this
work, we propose a liquid-metal-based triboelectric nanogenerator
(LM-TENG) by employing Galinstan as the electrode and silicone rubber
as the triboelectric and encapsulation layer. The small Young’s
modulus of the liquid metal ensures the electrode remains continuously
conductive under deformations, stretching to a strain as large as
∼300%. The surface oxide layer of Galinstan effectively prevents
the liquid Galinstan electrode from further oxidization and permeation
into silicone rubber, yielding outstanding device stability. Operating
in the single-electrode mode at 3 Hz, the LM-TENG with an area of
6 × 3 cm<sup>2</sup> produces an open-circuit voltage of 354.5
V, transferred short-circuit charge of 123.2 nC, short-circuit current
of 15.6 μA, and average power density of 8.43 mW/m<sup>2</sup>, which represent outstanding performance values for TENGs. Further,
the LM-TENG maintains stable performance under various deformations,
such as stretching, folding, and twisting. LM-TENGs in different forms,
such as bulk-shaped, bracelet-like, and textile-like, are all able
to harvest mechanical energy from human walking, arm shaking, or hand
patting to sustainably drive wearable electronic devices
Liquid-Metal-Based Super-Stretchable and Structure-Designable Triboelectric Nanogenerator for Wearable Electronics
The
rapid advancement of intelligent wearable electronics imposes
the emergent requirement for power sources that are deformable, compliant,
and stretchable. Power sources with these characteristics are difficult
and challenging to achieve. The use of liquid metals as electrodes
may provide a viable strategy to produce such power sources. In this
work, we propose a liquid-metal-based triboelectric nanogenerator
(LM-TENG) by employing Galinstan as the electrode and silicone rubber
as the triboelectric and encapsulation layer. The small Young’s
modulus of the liquid metal ensures the electrode remains continuously
conductive under deformations, stretching to a strain as large as
∼300%. The surface oxide layer of Galinstan effectively prevents
the liquid Galinstan electrode from further oxidization and permeation
into silicone rubber, yielding outstanding device stability. Operating
in the single-electrode mode at 3 Hz, the LM-TENG with an area of
6 × 3 cm<sup>2</sup> produces an open-circuit voltage of 354.5
V, transferred short-circuit charge of 123.2 nC, short-circuit current
of 15.6 μA, and average power density of 8.43 mW/m<sup>2</sup>, which represent outstanding performance values for TENGs. Further,
the LM-TENG maintains stable performance under various deformations,
such as stretching, folding, and twisting. LM-TENGs in different forms,
such as bulk-shaped, bracelet-like, and textile-like, are all able
to harvest mechanical energy from human walking, arm shaking, or hand
patting to sustainably drive wearable electronic devices
Liquid-Metal-Based Super-Stretchable and Structure-Designable Triboelectric Nanogenerator for Wearable Electronics
The
rapid advancement of intelligent wearable electronics imposes
the emergent requirement for power sources that are deformable, compliant,
and stretchable. Power sources with these characteristics are difficult
and challenging to achieve. The use of liquid metals as electrodes
may provide a viable strategy to produce such power sources. In this
work, we propose a liquid-metal-based triboelectric nanogenerator
(LM-TENG) by employing Galinstan as the electrode and silicone rubber
as the triboelectric and encapsulation layer. The small Young’s
modulus of the liquid metal ensures the electrode remains continuously
conductive under deformations, stretching to a strain as large as
∼300%. The surface oxide layer of Galinstan effectively prevents
the liquid Galinstan electrode from further oxidization and permeation
into silicone rubber, yielding outstanding device stability. Operating
in the single-electrode mode at 3 Hz, the LM-TENG with an area of
6 × 3 cm<sup>2</sup> produces an open-circuit voltage of 354.5
V, transferred short-circuit charge of 123.2 nC, short-circuit current
of 15.6 μA, and average power density of 8.43 mW/m<sup>2</sup>, which represent outstanding performance values for TENGs. Further,
the LM-TENG maintains stable performance under various deformations,
such as stretching, folding, and twisting. LM-TENGs in different forms,
such as bulk-shaped, bracelet-like, and textile-like, are all able
to harvest mechanical energy from human walking, arm shaking, or hand
patting to sustainably drive wearable electronic devices
Liquid-Metal-Based Super-Stretchable and Structure-Designable Triboelectric Nanogenerator for Wearable Electronics
The
rapid advancement of intelligent wearable electronics imposes
the emergent requirement for power sources that are deformable, compliant,
and stretchable. Power sources with these characteristics are difficult
and challenging to achieve. The use of liquid metals as electrodes
may provide a viable strategy to produce such power sources. In this
work, we propose a liquid-metal-based triboelectric nanogenerator
(LM-TENG) by employing Galinstan as the electrode and silicone rubber
as the triboelectric and encapsulation layer. The small Young’s
modulus of the liquid metal ensures the electrode remains continuously
conductive under deformations, stretching to a strain as large as
∼300%. The surface oxide layer of Galinstan effectively prevents
the liquid Galinstan electrode from further oxidization and permeation
into silicone rubber, yielding outstanding device stability. Operating
in the single-electrode mode at 3 Hz, the LM-TENG with an area of
6 × 3 cm<sup>2</sup> produces an open-circuit voltage of 354.5
V, transferred short-circuit charge of 123.2 nC, short-circuit current
of 15.6 μA, and average power density of 8.43 mW/m<sup>2</sup>, which represent outstanding performance values for TENGs. Further,
the LM-TENG maintains stable performance under various deformations,
such as stretching, folding, and twisting. LM-TENGs in different forms,
such as bulk-shaped, bracelet-like, and textile-like, are all able
to harvest mechanical energy from human walking, arm shaking, or hand
patting to sustainably drive wearable electronic devices
Liquid-Metal-Based Super-Stretchable and Structure-Designable Triboelectric Nanogenerator for Wearable Electronics
The
rapid advancement of intelligent wearable electronics imposes
the emergent requirement for power sources that are deformable, compliant,
and stretchable. Power sources with these characteristics are difficult
and challenging to achieve. The use of liquid metals as electrodes
may provide a viable strategy to produce such power sources. In this
work, we propose a liquid-metal-based triboelectric nanogenerator
(LM-TENG) by employing Galinstan as the electrode and silicone rubber
as the triboelectric and encapsulation layer. The small Young’s
modulus of the liquid metal ensures the electrode remains continuously
conductive under deformations, stretching to a strain as large as
∼300%. The surface oxide layer of Galinstan effectively prevents
the liquid Galinstan electrode from further oxidization and permeation
into silicone rubber, yielding outstanding device stability. Operating
in the single-electrode mode at 3 Hz, the LM-TENG with an area of
6 × 3 cm<sup>2</sup> produces an open-circuit voltage of 354.5
V, transferred short-circuit charge of 123.2 nC, short-circuit current
of 15.6 μA, and average power density of 8.43 mW/m<sup>2</sup>, which represent outstanding performance values for TENGs. Further,
the LM-TENG maintains stable performance under various deformations,
such as stretching, folding, and twisting. LM-TENGs in different forms,
such as bulk-shaped, bracelet-like, and textile-like, are all able
to harvest mechanical energy from human walking, arm shaking, or hand
patting to sustainably drive wearable electronic devices