2 research outputs found
Synthesis of Low Pt-Based Quaternary PtPdRuTe Nanotubes with Optimized Incorporation of Pd for Enhanced Electrocatalytic Activity
Improving
heteroatomic interactions via alloying or forming heterogeneous
catalysts is of importance to the enhancement in terms of electrocatalytic
activity and stability. In this work, a simple galvanic replacement
reaction was utilized to synthesize low Pt-based quaternary nanotubes
(NTs). It is easy to obtain PtPdRuTe NTs with different composition
and controlled shape using ultrathin Te nanowires (NWs) as sacrificial
templates for its high activity. The NT wall thickness and formed
NPs on the surface are closely related with the composition, especially
Pd content. The optimized incorporation of Pd atoms into ternary PtRuTe
NTs formed a uniform protecting PtPd surface and modified the Pt electronic
structure to improve the methanol oxidation reaction (MOR) performance.
X-ray photoelectron spectroscopy (XPS) reveals a larger extent of
electron transfer from neighboring atoms to Pt on PtPdRuTe, consequently
leading to a weaker bonding of the intermediate on Pt. As a result,
the quaternary PtPdRuTe NTs exhibit enhanced activity and stability
toward efficient MOR
Bacterial Cellulose: A Robust Platform for Design of Three Dimensional Carbon-Based Functional Nanomaterials
ConspectusThree dimensional (3D) carbon nanomaterials
exhibit great application
potential in environmental protection, electrochemical energy storage
and conversion, catalysis, polymer science, and advanced sensors fields.
Current methods for preparing 3D carbon nanomaterials, for example,
carbonization of organogels, chemical vapor deposition, and self-assembly
of nanocarbon building blocks, inevitably involve some drawbacks,
such as expensive and toxic precursors, complex equipment and technological
requirements, and low production ability. From the viewpoint of practical
application, it is highly desirable to develop a simple, cheap, and
environmentally friendly way for fabricating 3D carbon nanomaterials
in large scale. On the other hand, in order to extend the application
scope and improve the performance of 3D carbon nanomaterials, we should
explore efficient strategies to prepare diverse functional nanomaterials
based on their 3D carbon structure.Recently, many researchers
tend to fabricate high-performance 3D
carbon-based nanomaterials from biomass, which is low cost, easy to
obtain, and nontoxic to humans. Bacterial cellulose (BC), a typical
biomass material, has long been used as the raw material of <i>nata-de-coco</i> (an indigenous dessert food of the Philippines).
It consists of a polysaccharide with a β-1,4-glycosidic linkage
and has a interconnected 3D porous network structure. Interestingly,
the network is made up of a random assembly of cellulose nanofibers,
which have a high aspect ratio with a diameter of 20–100 nm.
As a result, BC has a high specific surface area. Additionally, BC
hydrogels can be produced on an industrial scale via a microbial fermentation
process at a very low price. Thus, it can be an ideal platform for
design of 3D carbon-based functional nanomaterials. Before our work,
no systematic work and summary on this topic had been reported.This Account presents the concepts and strategies of our studies
on BC in the past few years, that is, converting cheap biomass into
high value-added 3D carbon nanomaterials and designing diverse functional
materials on 3D carbon structure. We first briefly introduce the history,
constituent, and microstructure features of BC and discuss its advantages
as a raw material for preparing the CNF aerogels. Then, we summarize
the methods and strategies for preparing various 3D carbon-based nanomaterials
from BC. In addition, the potential applications of the developed
CNF aerogel based functional materials are also highlighted in this
Account, including stretchable conductors, oxygen reduction reaction
catalysts, supercapacitors, lithium-ion battery, and oil cleanup.
Finally, we give some prospects on the future challenges in this emerging
research area of designing CNF aerogel based functional nanomaterials
from BC