4,647 research outputs found
Themed issue: Optofluidics
The term optofluidics defines a growing
research area that integrates optics and
microfluidics in ways that enable unique
strengths and advantages for a broad range
of applications. The First International
Conference on Optofluidics (Optofluidics-
2011) organized by Xi’an Jiaotong
University and Lab on a Chip on 11–12
December 2011 featured work in this field,
with an exciting two-day program of presentations
and discussions. We are happy
that Lab on a Chip, a major publication
destination for optofluidic research, has
scheduled this themed issue on Optofluidics.
We are especially heartened that the optofluidics
community has responded enthusiastically
with a large number of excellent
manuscript submissions
On the photofragmentation of SF: Experimental evidence for a predissociation channel
We report on the first observation of the photofragmentation dynamics of
SF. With the aid of state-of-the-art ab initio calculations on the
low-lying excited cationic states of SF performed by Lee et al. [J. Chem.
Phys. 125, 104304 (2006)], a predissociation channel of SF is evidenced
by means of resonance-enhanced multilphoton ionization spectroscopy. This work
represents a second experimental investigation on the low-lying excited
cationic states of SF. [The first one is the He I photoelectron spectrum
of SF reported by de Leeuw et al. three decades ago, see Chem. Phys. 34,
287 (1978).]Comment: 7 pages, 3 figures, submitted to JCP as a Not
The rise of topologically non-trivial materials for hydrogen evolution electrocatalysts
In the mid-2000s, a new quantum state of topological insulators was proposed. It deeply refreshed the traditional understanding of electronic band structure, which has been the most fundamental tool to classify metals and insulators. Topological insulators with non-trivial topological charges can host robust surface states or edge states located in the bulk bandgap. To understand this new state, an understanding of the bandgap is not sufficient, and it led to the new field of topological band theory in condensed matter physics. The development of electronic band structure theory also inspired the understanding of topological band theory from the chemical point of view and results in the new topic of topological chemistry.
The discovery of topological insulators motivated extensive studies of solid-state materials from topological theory, leading to many topological materials in both insulators and metals. In the last 15 years, various topological materials characterized by different topological electronic structures have been discovered. One of the most important features shared by all different topological materials is the topologically protected non-trivial surface states (TSSs). Such TSSs are essentially different from the dangling bonds because they connect to conduction bands and valence bands in insulators or bulk band crossings in metals. The extra perturbation
can only change their detailed shape but not remove them. This characteristic makes
TSSs attractive for practical applications in the quantum information process, data storage, and energy conversion. In particular, the robust surface state is an attractive property that benefits energy-related catalysis. The last few years have seen research in this field with a focus on developing efficient topological material catalysts for hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and reduction. To date, the topological catalyst has become a new frontier in both chemistry and materials science.
Within the scope of this Ph.D. thesis, several topological semimetals and their HER activity are studied with the help of density functional theory, electrochemical theory, and topological band theory, combined with experimental measurements performed within the workgroup. The spectrum of performed projects ranges from the theoretical design of the high-efficiency hydrogen evolution catalyst with the guidance of topology in close collaboration with experiments and in-depth understanding of the relationship between topological properties and catalysis
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