X-ray-activated long persistent phosphors featuring strong UVC afterglow emissions

Phosphors emitting visible and near-infrared persistent luminescence have been explored extensively owing to their unusual properties and commercial interest in their applications such as glow-in-the-dark paints,optical information storage,and in vivo bioimaging.However,no persistent phosphor that features emissions in the ultraviolet C range(200–280 nm)has been known to exist so far.Here,we demonstrate a strategy for creating a new generation of persistent phosphor that exhibits strong ultraviolet C emission with an initial power density over 10 milliwatts per square meter and an afterglow of more than 2 h.Experimental characterizations coupled with first-principles calculations have revealed that structural defects associated with oxygen introduction-induced anion vacancies in fluoride elpasolite can function as electron traps,which capture and store a large number of electrons triggered by Xray irradiation.Notably,we show that the ultraviolet C afterglow intensity of the yielded phosphor is sufficiently strong for sterilization.Our discovery of this ultraviolet C afterglow opens up new avenues for research on persistent phosphors,and it offers new perspectives on their applications in terms of sterilization,disinfection,drug release,cancer treatment,anti-counterfeiting,and beyond.

Heterostructures of NiFe LDH hierarchically assembled on MoS_(2) nanosheets as high-efficiency electrocatalysts for overall water splitting

Typically,rational interfacial engineering can effectively modify the adsorption energy of active hydrogen molecules to improve water splitting efficiency.NiFe layered double hydroxide(NiFe LDH)composite,an efficient oxygen evolution reaction(OER)catalyst,suffers from slow hydrogen evolution reaction(HER)kinetics,restricting its application for overall water splitting.Herein,we construct the hierarchical MoS_(2)/NiFe LDH nanosheets with a heterogeneous interface used for HER and OER.Benefiting the hierarchical heterogeneous interface optimized hydrogen Gibbs free energy,tens of exposed active sites,rapid mass-and charge-transfer processes,the MoS_(2)/NiFe LDH displays a highly efficient synergistic electrocatalytic effect.The MoS_(2)/NiFe LDH electrode in 1 mol/L KOH exhibits excellent HER activity,only 98 mV overpotential at 10 mA/cm^(2).Significantly,when it assembled as anode and cathode for overall water splitting,only 1.61 V cell voltage was required to achieve 10 mA/cm^(2)with excellent durability(50 h).

Integration of Fe_(2)O_(3)-based photoanode and atomically dispersed cobalt cathode for efficient photoelectrochemical NH_(3) synthesis

Realizing nitrogen reduction reaction(NRR) to synthesis NH_(3) under mild conditions has gained extensive attention as a promising alternative way to the energy-and emission-intensive Haber-Bosch process.Among varieties of potential strategies,photoelectrochemical(PEC) NRR exhibits many advantages including utilization of solar energy,water(H_(2)O) as the hydrogen source and ambient operation conditions.Herein,we have designed a solar-driven PEC-NRR system integrating high-efficiency Fe_(2)O_(3)-based photoanode and atomically dispersed cobalt(Co) cathode for ambient NH3 synthesis.Using such solar-driven PEC-NRR system,high-efficiency Fe_(2)O_(3)-based photoanode is responsible for H_(2)O/OH oxidatio n,and meanwhile the generated photoelectrons transfer to the single-atom Co cathode for the N_(2) reduction to NH_(3).As a result,this system can afford an NH_(3) yield rate of 1021.5 μg mg_(co)^(-1) h^(-1) and a faradic efficiency of 11.9% at an applied potential bias of 1.2 V(versus reversible hydrogen electrode) on photoanode in 0.2 mol/L NaOH electrolyte under simulated sunlight irradiation.

Grey hematite photoanodes decrease the onset potential in photoelectrochemical water oxidation

Photoelectrochemical(PEC)water splitting for solar energy conversion into chemical fuels has attracted intense research attention.The semiconductor hematite(α-Fe_(2)O_(3)),with its earth abundance,chemical stability,and efficient light harvesting,stands out as a promising photoanode material.Unfortunately,its electron affinity is too deep for overall water splitting,requiring additional bias.Interface engineering has been used to reduce the onset potential of hematite photoelectrode.Here we focus instead on energy band engineering hematite by shrinking the crystal lattice,and the water-splitting onset potential can be decreased from 1.14 to 0.61 V vs.the reversible hydrogen electrode.It is the lowest record reported for a pristine hematite photoanode without surface modification.X-ray absorption spectroscopy and magnetic properties suggest the redistribution of 3d electrons in the as-synthesized grey hematite electrode.Density function theory studies herein show that the smaller-lattice-constant hematite benefits from raised energy bands,which accounts for the reduced onset potential.

Combining Neutron Scattering,Deuteration Technique,and Molecular Dynamics Simulations to Study Dynamics of Protein and Its Surface Water Molecules

Protein internal dynamics is essential for its function. Exploring the internal dynamics of protein molecules as well as its connection to protein structure and function is a central topic in biophysics. However, the atomic motions in protein molecules exhibit a great degree of complexities. These complexities arise from the complex chemical composition and superposition of different types of atomic motions on the similar time scales, and render it challenging to explicitly understand the microscopic mechanism governing protein motions, functions, and their connections. Here, we demonstrate that, by using neutron scattering, molecular dynamics simulation, and deuteration technique, one can address this challenge to a large extent.

Design and simulation of a standing wave oscillator based PLL

A standing wave oscillator(SWO) is a perfect clock source which can be used to produce a high frequency clock signal with a low skew and high reliability. However, it is difficult to tune the SWO in a wide range of frequencies. We introduce a frequency tunable SWO which uses an inversion mode metal-oxide-semiconductor(IMOS) field-effect transistor as a varactor, and give the simulation results of the frequency tuning range and power dissipation. Based on the frequency tunable SWO, a new phase locked loop(PLL) architecture is presented. This PLL can be used not only as a clock source, but also as a clock distribution network to provide high quality clock signals. The PLL achieves an approximately 50% frequency tuning range when designed in Global Foundry 65 nm 1P9 M complementary metal-oxide-semiconductor(CMOS) technology, and can be used directly in a high performance multi-core microprocessor.