Synthesis of Zn-Doped AgInS₂ Nanocrystals and Their Fluorescence Properties

AgInS₂ nanocrystals have attracted intense attention due to their promising applications in printable solar cells, light-emitting diode (LED), and biological labeling. Although much effort has been made to develop various synthesis methods to prepare AgInS₂ nanocrystals, it remains a goal to obtain high quality AgInS₂ nanocrystals. In this work, Zn-doped AgInS₂ nanocrystals were synthesized by diffusing Zn into the preformed AgInS₂ seeds at high temperature in solution. The resulting Zn-doped AgInS₂ nanocrystals had well-defined spherical morphology with narrow size distribution. By varying the reaction temperature, the emission wavelengths of the obtained Zn-doped AgInS₂ nanocrystals could be adjusted from 520 to 680 nm. The quantum yield of the obtained alloyed nanocrystals could reach 41%, which was reasonably good as compared to those of the previously reported. The obtained Zn-doped AgInS₂ nanocrystals showed promising applications in cell labeling

Low Li⁺ Insertion Barrier Carbon for High Energy Efficient Lithium-Ion Capacitor

Lithium-ion capacitor (LIC) is an attractive energy-storage device (ESD) that promises high energy density at moderate power density. However, the key challenge in its design is the low energy efficient negative electrode, which barred the realization of such research system in fulfilling the current ESD technological inadequacy due to its poor overall energy efficiency. Large voltage hysteresis is the main issue behind high energy density alloying/conversion-type materials, which reduces the electrode energy efficiency. Insertion-type material though averted in most research due to the low capacity remains to be highly favorable in commercial application due to its lower voltage hysteresis. To further reduce voltage hysteresis and increase capacity, amorphous carbon with wider interlayer spacing has been demonstrated in the simulation result to significantly reduce Li⁺ insertion barrier. Hence, by employing such amorphous carbon, together with disordered carbon positive electrode, a high energy efficient LIC with round-trip energy efficiency of 84.3% with a maximum energy density of 133 Wh kg^–1 at low power density of 210 W kg^–1 can be achieved

Synthesis of Water-Dispersible Gd₂O₃/GO Nanocomposites with Enhanced MRI <i>T</i>₁ Relaxivity

Water-dispersible Gd₂O₃ (GDO) nanoparticles decorated graphene oxide (GO) nanocomposites (or GDO/GO NCs) were successfully synthesized as novel magnetic resonance imaging contrast agents. The nanocomposites were prepared through a facile solvent evaporation method. The hydrodynamic size of the resultant nanocomposites could be adjusted easily by varying the sonication pretreatment time. When measured using 7 T MRI scanner, the relaxivity value (<i>r</i>₁) of the GDO/GO NCs was as high as 34.48 mM^–1 s^–1, which is much higher than those of the typical commercial MRI <i>T</i>₁ contrast agent materials such as Gd-DOTA and Gd-DTPA. The cytotoxicity study showed that the GDO/GO NCs exhibited better biocompatibility as compared to the previously reported Gd-based MRI contrast agents. It was demonstrated that GDO/GO NCs were promising as magnetic resonance imaging (MRI) <i>T</i>₁ contrast agents

Increasing Gas Bubble Escape Rate for Water Splitting with Nonwoven Stainless Steel Fabrics

Water electrolysis has been considered as one of the most efficient approaches to produce renewable energy, although efficient removal of gas bubbles during the process is still challenging, which has been proved to be critical and can further promote electrocatalytic water splitting. Herein, a novel strategy is developed to increase gas bubble escape rate for water splitting by using nonwoven stainless steel fabrics (NWSSFs) as the conductive substrate decorated with flakelike iron nickel-layered double hydroxide (FeNi LDH) nanostructures. The as-prepared FeNi LDH@NWSSF electrode shows a much faster escape rate of gas bubbles as compared to that of other commonly used three-dimensional porous catalytic electrodes, and the maximum dragging force for a bubble releasing between NWSSF channels is only one-seventh of the dragging force within nickel foam channels. As a result, it exhibits excellent electrocatalytic performance for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), with low overpotentials of 210 and 110 mV at the current density of 10 mA cm^–2 in 1 M KOH for OER and HER, respectively. There is almost no current drop after a long-time durability test. In addition, its performance for full water splitting is superior to that of the previously reported catalysts, with a voltage of 1.56 V at current density of 10 mA cm^–2

Increasing Gas Bubble Escape Rate for Water Splitting with Nonwoven Stainless Steel Fabrics

Water electrolysis has been considered as one of the most efficient approaches to produce renewable energy, although efficient removal of gas bubbles during the process is still challenging, which has been proved to be critical and can further promote electrocatalytic water splitting. Herein, a novel strategy is developed to increase gas bubble escape rate for water splitting by using nonwoven stainless steel fabrics (NWSSFs) as the conductive substrate decorated with flakelike iron nickel-layered double hydroxide (FeNi LDH) nanostructures. The as-prepared FeNi LDH@NWSSF electrode shows a much faster escape rate of gas bubbles as compared to that of other commonly used three-dimensional porous catalytic electrodes, and the maximum dragging force for a bubble releasing between NWSSF channels is only one-seventh of the dragging force within nickel foam channels. As a result, it exhibits excellent electrocatalytic performance for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), with low overpotentials of 210 and 110 mV at the current density of 10 mA cm^–2 in 1 M KOH for OER and HER, respectively. There is almost no current drop after a long-time durability test. In addition, its performance for full water splitting is superior to that of the previously reported catalysts, with a voltage of 1.56 V at current density of 10 mA cm^–2

Increasing Gas Bubble Escape Rate for Water Splitting with Nonwoven Stainless Steel Fabrics

Water electrolysis has been considered as one of the most efficient approaches to produce renewable energy, although efficient removal of gas bubbles during the process is still challenging, which has been proved to be critical and can further promote electrocatalytic water splitting. Herein, a novel strategy is developed to increase gas bubble escape rate for water splitting by using nonwoven stainless steel fabrics (NWSSFs) as the conductive substrate decorated with flakelike iron nickel-layered double hydroxide (FeNi LDH) nanostructures. The as-prepared FeNi LDH@NWSSF electrode shows a much faster escape rate of gas bubbles as compared to that of other commonly used three-dimensional porous catalytic electrodes, and the maximum dragging force for a bubble releasing between NWSSF channels is only one-seventh of the dragging force within nickel foam channels. As a result, it exhibits excellent electrocatalytic performance for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), with low overpotentials of 210 and 110 mV at the current density of 10 mA cm^–2 in 1 M KOH for OER and HER, respectively. There is almost no current drop after a long-time durability test. In addition, its performance for full water splitting is superior to that of the previously reported catalysts, with a voltage of 1.56 V at current density of 10 mA cm^–2

From Titanium Sesquioxide to Titanium Dioxide: Oxidation-Induced Structural, Phase, and Property Evolution

In contrast to Ti⁴⁺-containing titanium dioxide (TiO₂), which has a wide bandgap (∼3.0 eV) and has been widely explored for catalysis and energy applications, titanium sesquioxide (Ti₂O₃) with an intermediate valence state (Ti³⁺) possesses an ultranarrow bandgap (∼0.1 eV) and has been much less investigated. Although the importance of Ti³⁺ to the applications of TiO₂ is widely recognized, the connection between TiO₂ and Ti₂O₃ and the transformation pathway remain unknown. Herein, we investigate the oxidation-induced structural, phase, and property evolution of Ti₂O₃ using a complementary suite of microscopic and spectroscopic tools. Interestingly, transformation pathways to both rutile and anatase TiO₂ are identified, which sensitively depend on oxidation conditions. Unique Ti₂O₃/TiO₂ core–shell structures with annealing-controlled surface nanostructure formation are observed for the first time. The compositional and structural evolution of Ti₂O₃/TiO₂ particles is accompanied by continuously tuned optical and electrical properties. Overall, our work reveals the connection between narrow-bandgap Ti³⁺-containing Ti₂O₃ and wide-bandgap Ti⁴⁺-containing TiO₂, providing a versatile platform for exploring photoelectrocatalytic applications in valence- and structure-tailored oxide materials