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Directional Mn dopant migration (outward/inward) was achieved by inserting a CdZnS “atomic trap” with a small size mismatch with dopants in core/multi-shell QDs. A larger initial substitutional site allows for active trapping and dopant migration.

 

Online innovation competitions are ecosystems where institutions source numerous solutions from knowledge workers through a platform intermediary. By considering how an individual competitor’s performance varies based on their social positioning in a competition ecosystem’s collaboration network, we illustrate the value of social networks for individual outcomes in online competitions. The study reports results from Kaggle, a popular online competition platform for data science, where a sample of 350,956 users participated in 2,789 competitions over 4 years. We investigate how the number of collaborations, membership in the largest connected component in the network, and diversity of collaboration experiences impact the points and medals earned and how quickly competitors earn their first medal. Results show that positioning has a positive relationship with performance in competitive ecosystems. Relevant to the future of work, the study considers how knowledge workers in future workplaces should manage their online collaborations.

 

Using sunlight to produce hydrogen gas via photocatalytic water splitting is highly desirable for green energy harvesting and sustainability. In this work, Mn 2+ doped 1-dimensional (1D) CdS nanorods (NRs) with Pt tips ( i.e. , 1D Mn:CdS-Pt NRs) were synthesized for photocatalytic water splitting to generate hydrogen gas. The incorporation of Mn 2+ dopants inside the 1D CdS NRs with a significantly longer lifetime (∼ms) than that of host excitons (∼ns) facilitates charge separation; the electron transfer to metal Pt tips leads to enhanced photocatalytic activity in water splitting redox reactions. The as-synthesized Mn 2+ doped CdS NR-based photocatalyst generated an order of magnitude greater yield of hydrogen gas compared to the undoped CdS NR-based photocatalyst. The enhanced charge transport from the long lifetime excited state of Mn 2+ dopants in light harvesting semiconductor nanomaterials presents a new opportunity to increase the overall photocatalytic performance. 

The high bond dissociation energy of C–C σ-bonds presents a challenge to chemical conversions in organic synthesis, polymer degradation, and biomass conversion that require chemoselective C–C bond cleavage at room temperature. Dye-sensitized photoelectrochemical cells (DSPECs) incorporating molecular organic dyes could offer a means of using renewable solar energy to drive these types of energetically demanding chemoselective C–C bond cleavage reactions. This study reports the solar light-driven activation of a bicyclic aminoxyl mediator to achieve C–C bond cleavage in the aryl-ether linkage of a lignin model compound (LMC) at room temperature using a donor–π-conjugated bridge–acceptor (D–π–A) organic dye-based DSPEC system. Mesoporous TiO 2 photoanode surfaces modified with 5-[4-(diphenylamino)phenyl]thiophene-2-cyanoacrylic acid (DPTC) D–π–A organic dye were investigated along with a bicyclic aminoxyl radical mediator (9-azabicyclo[3,3,1]nonan-3-one-9-oxyl, KABNO) in solution with and without the presence of LMC. Photophysical studies of DPTC with KABNO showed intermolecular energy/electron transfer under 1 sun illumination (100 mW cm −2 ). Under illumination, the D–π–A type DPTC sensitized TiO 2 photoanodes facilitate the generation of the reactive oxoammonium species KABNO+ as a strong oxidizing agent, which is required to drive the oxidative C–C bond cleavage of LMC. The photoelectrochemical oxidative reaction in a complete DSPEC with KABNO afforded C–C bond cleavage products 2-(2-methoxyphenoxy)acrylaldehyde (94%) and 2,6-dimethoxy-1,4-benzoquinone (66%). This process provides a first report utilizing a D–π–A type organic dye in combination with a bicyclic nitroxyl radical mediator for heterogeneous photoelectrolytic oxidative cleavage of C–C σ-bonds, modeled on those found in lignin, at room temperature. 

All‐inorganic lead halide perovskite nanocrystals (NCs) have great optoelectronic properties with promising applications in light‐emitting diodes (LEDs), lasers, photodetectors, solar cells, and photocatalysis. However, the intrinsic toxicity of Pb and instability of the NCs impede their broad applications. Shell‐coating is an effective method for enhanced environmental stability while reducing toxicity by choosing non‐toxic shell materials such as metal oxides, polymers, silica, etc. However, multiple perovskite NCs can be encapsulated within the shell material and a uniform epitaxial‐type shell growth of well‐isolated NCs is still challenging. In this work, lead‐free vacancy‐ordered double perovskite Cs₂SnX₆(X = Cl, Br, and I) shells are epitaxially grown on the surface of CsPbX₃NCs by a hot‐injection method. The effectiveness of the non‐toxic double perovskite shell protection is demonstrated by the enhanced environmental and phase stability against UV illumination and water. In addition, the photoluminescence quantum yields (PL QYs) increase for the CsPbCl₃and CsPbBr₃NCs after shelling because of the type I band alignment of the core/shell materials, while enhanced charge transport properties obtained from CsPbI₃/Cs₂SnI₆core/shell NCs are due to the efficient charge separation in the type II core/shell band alignment.