32 research outputs found
Acid-Base Interaction Enhancing Oxygen Tolerance in Electrocatalytic Carbon Dioxide Reduction
High-performance electrochemical CO2 reduction cells based on non-noble metal catalysts
The promise and challenge of electrochemical mitigation of CO2 calls for innovations on both catalyst and reactor levels. In this work, enabled by our high-performance and earth-abundant CO2 electroreduction catalyst materials, we developed alkaline microflow electrolytic cells for energy-efficient, selective, fast, and durable CO2 conversion to CO and HCOO-. With a cobalt phthalocyanine-based cathode catalyst, the CO-selective cell starts to operate at a 0.26 V overpotential and reaches a Faradaic efficiency of 94% and a partial current density of 31 mA/cm2 at a 0.56 V overpotential. With a SnO2-based cathode catalyst, the HCOO--selective cell starts to operate at a 0.76 V overpotential and reaches a Faradaic efficiency of 82% and a partial current density of 113 mA/cm2 at a 1.36 V overpotential. In contrast to previous studies, we found that the overpotential reduction from using the alkaline electrolyte is mostly contributed by a pH gradient near the cathode surface
Spontaneous rotational symmetry breaking in KTaO interface superconductors
Strongly correlated electrons could display intriguing spontaneous broken
symmetries in the ground state. Understanding these symmetry breaking states is
fundamental to elucidate the various exotic quantum phases in condensed matter
physics. Here, we report an experimental observation of spontaneous rotational
symmetry breaking of the superconductivity at the interface of
YAlO/KTaO (111) with a superconducting transition temperature of 1.86
K. Both the magnetoresistance and upper critical field in an in-plane field
manifest striking twofold symmetric oscillations deep inside the
superconducting state, whereas the anisotropy vanishes in the normal state,
demonstrating that it is an intrinsic property of the superconducting phase. We
attribute this behavior to the mixed-parity superconducting state, which is an
admixture of -wave and -wave pairing components induced by strong
spin-orbit coupling. Our work demonstrates an unconventional nature of the
pairing interaction in the KTaO interface superconductor, and provides a
new platform to clarify a delicate interplay of electron correlation and
spin-orbit coupling.Comment: 7 pages, 4 figure
Proximity effect induced intriguing superconductivity in van der Waals heterostructure of magnetic topological insulator and conventional superconductor
Nontrivial topological superconductivity has received enormous research
attentions due to its potential for diverse applications in topological quantum
computing. The intrinsic issue concerning the correlation between a topological
insulator and a superconductor is, however, still widely open. Here, we
systemically report an emergent superconductivity in a cross-junction composed
of a magnetic topological insulator MnBi2Te4 and a conventional superconductor
NbSe2. Remarkably, the interface indicates existence of a reduced
superconductivity at surface of NbSe2 and a proximity-effectinduced
superconductivity at surface of MnBi2Te4. Furthermore, the in-plane
angular-dependent magnetoresistance measurements reveal the fingerprints of the
paring symmetry behaviors for these superconducting gaps as a unconventional
nature. Our findings extend our views and ideas of topological
superconductivity in the superconducting heterostructures with time-reversal
symmetry breaking, offering an exciting opportunity to elucidate the
cooperative effects on the surface state of a topological insulator aligning a
superconductor.Comment: 6 pages, 4 figure
Non-Standard Errors
In statistics, samples are drawn from a population in a data-generating process (DGP). Standard errors measure the uncertainty in estimates of population parameters. In science, evidence is generated to test hypotheses in an evidence-generating process (EGP). We claim that EGP variation across researchers adds uncertainty: Non-standard errors (NSEs). We study NSEs by letting 164 teams test the same hypotheses on the same data. NSEs turn out to be sizable, but smaller for better reproducible or higher rated research. Adding peer-review stages reduces NSEs. We further find that this type of uncertainty is underestimated by participants