| 1. |
- An, Rui, et al.
(författare)
-
Photostability and Photodegradation Processes in Colloidal CsPbI3 Perovskite Quantum Dots
- 2018
-
Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 10:45, s. 39222-39227
-
Tidskriftsartikel (refereegranskat)abstract
- All-inorganic CsPbI3 perovskite quantum dots (QDs) have attracted intense attention for their successful application in photovoltaics (PVs) and optoelectronics that are enabled by their superior absorption capability and great photoluminescence (PL) properties. However, their photostability remains a practical bottleneck and further optimization is highly desirable. Here, we studied the photostability of as-obtained colloidal CsPbI3 QDs suspended in hexane. We found that light illumination does induce photodegradation of CsPbI3 QDs. Steady-state spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, and transient absorption spectroscopy verified that light illumination leads to detachment of the capping agent, collapse of the CsPbI3 QD surface, and finally aggregation of surface Pb0. Both dangling bonds containing surface and Pb0 serve as trap states causing PL quenching with a dramatic decrease of PL quantum yield. Our work provides a detailed insight about the correlation between the structural and photophysical consequences of the photodegradation process in CsPbI3 QDs and may lead to the optimization of such QDs toward device applications.
|
|
| 2. |
- Beal, Jacob, et al.
(författare)
-
Robust estimation of bacterial cell count from optical density
- 2020
-
Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
-
Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
|
|
| 3. |
- Dan, Meng, et al.
(författare)
-
A dual-interfacial system with well-defined spatially separated redox-sites for boosting photocatalytic overall H2S splitting
- 2021
-
Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947. ; 423
-
Tidskriftsartikel (refereegranskat)abstract
- Integration of high activity, selectivity, and stability is urgently desired to achieve more ideal photocatalysts. Herein, we reported the rational design of MoS2-MnS@(InxCu1-x)2S3 (M-M@IC) catalysts with dual interface to integrate separated redox sites for boosting photocatalytic hydrogen sulphide (H2S) splitting and the resource utilization of sacrificial reagents (Na2S/Na2SO3). The spatially separated reduction (MnS) and oxidation (In2S3) sites in MnS/In2S3 heterojunction, on which MoS2 and Cu were selectively loaded, can drive electrons and holes near the surface to flow along opposite directions, while the heterojunction between MnS and In2S3 inhibits the bulk charge recombination. Furthermore, the introduction of Cu atoms creates a d-band center, which favours mass diffusion of reactants/products species and greatly facilitates sunlight response. The MoS2 serves to provide abundant sites for proton reduction due to the unsaturated-sulfur-edge-rich (US-rich) nature. As a result, the M−M@IC shows a state-of-the-art visible-light photocatalytic H2 evolution rate (126.5 mmol g-1h−1), inspiring stability of >50 h, and nearly 100% selectivity toward value-added Na2S2O3 production under optimized condition. This work opens up new opportunities for the construction and design of spatially separated catalytic site in photocatalysts.
|
|
| 4. |
- Dan, Meng, et al.
(författare)
-
Beyond hydrogen production : Solar−driven H2S−donating value−added chemical production over MnxCd1−xS/CdyMn1−yS catalyst
- 2021
-
Ingår i: Applied Catalysis B: Environmental. - : Elsevier BV. - 0926-3373. ; 284
-
Tidskriftsartikel (refereegranskat)abstract
- Simultaneous hydrogen (H2) evolution and value−added chemicals production are highly attractive but have not drawn enough attention. Here, we demonstrate a hydrogen sulphide (H2S)−induced product−targeting (HIPT) strategy for the coproduction of H2 and valuable chemical feedstocks from Na2S/Na2SO3 via overall H2S splitting using a MnxCd1−xS/CdyMn1−yS catalyst driven by visible light excitation. With this chemistry, 113 mmol g−1 h−1 of hydrogen evolution rate is achieved, surpassing most of the previously reported state-of-the-art photocatalyst, together with the production of value−added Na2S2O3 with nearly 100% selectivity. This work not only provides a good example for solar energy conversion via overall H2S splitting, but also offers new insights into the resource utilization of sacrificial donor (Na2S/Na2SO3) in various catalytic fields such as H2O splitting and CO2 reduction.
|
|
