Preparation of SnS2 colloidal quantum dots and their application in organic/inorganic hybrid solar cells

Dispersive SnS2 colloidal quantum dots have been synthesized via hot-injection method. Hybrid photovoltaic devices based on blends of a conjugated polymer poly[2-methoxy-5-(3",7"dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) as electron donor and crystalline SnS2 quantum dots as electron acceptor have been studied. Photoluminescence measurement has been performed to study the surfactant effect on the excitons splitting process. The photocurrent of solar cells with the hybrid depends greatly on the ligands exchange as well as the device heat treatment. AFM characterization has demonstrated morphology changes happening upon surfactant replacement and annealing, which can explain the performance variation of hybrid solar cells

Confinement of carbon dots localizing to the ultrathin layered double hydroxides toward simultaneous triple-mode bioimaging and photothermal therapy

It is a great challenge to develop multifunctional nanocarriers for cancer diagnosis and therapy. Herein, versatile CDs/ICG-uLDHs nanovehicles for triple-modal fluorescence/photoacoustic/two-photon bioimaging and effective photothermal therapy were prepared via a facile self-assembly of red emission carbon dots (CDs), indocyanine green (ICG) with the ultrathin layered double hydroxides (uLDHs). Due to the J-aggregates of ICG constructed in the self-assembly process, CDs/ICG-uLDHs was able to stabilize the photothermal agent ICG and enhanced its photothermal efficiency. Furthermore, the unique confinement effect of uLDHs has extended the fluorescence lifetime of CDs in favor of bioimaging. Considering the excellent in vitro and in vivo phototherapeutics and multimodal imaging effects, this work provides a promising platform for the construction of multifunctional theranostic nanocarrier system for the cancer treatment

Preparation of SnS₂colloidal quantum dots and their application in organic/inorganic hybrid solar cells

Abstract Dispersive SnS2 colloidal quantum dots have been synthesized via hot-injection method. Hybrid photovoltaic devices based on blends of a conjugated polymer poly[2-methoxy-5-(3",7"dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) as electron donor and crystalline SnS2 quantum dots as electron acceptor have been studied. Photoluminescence measurement has been performed to study the surfactant effect on the excitons splitting process. The photocurrent of solar cells with the hybrid depends greatly on the ligands exchange as well as the device heat treatment. AFM characterization has demonstrated morphology changes happening upon surfactant replacement and annealing, which can explain the performance variation of hybrid solar cells.</p

Fast-response oxygen sensitive transparent coating for inner pressure ratiometric optical mapping

In this work, dual-luminophore self-referenced pressure sensitive paint (PSP) was prepared with siloxane precursors by using copolymerizable silane-functionalized carbon dots (SiCDs) as a reference probe and a newly synthesized silane-modified ruthenium complex (Ru-silane) as the sensitive probe respectively. The PSP is fully sprayable in the preparation of bi-layer thin coatings via a sol-gel process, by which a SiCD copolymerized silicone base layer was firstly constructed and subsequently covered by a Ru-silane grafted top layer. The resultant optical sensor is transparent, having a transmittance as high as 80%, besides the chemical bonding of the probes had favorably improved the stability of the luminescence properties. Based on the oxygen quenching mechanism, such transparent PSP coatings allowed efficient determination of the sudden changes of surface pressure in an inner flow channel with a time response of 1.3 ms, while the measurement can be performed from either the front side or the reverse side of the coating. Furthermore, the 2D pressure map can be quantified by calculating the intensity ratio of SiCDs to Ru-silane photoluminescence and thereby improved the accuracy of the measurement. We thus expect the transparent PSP coatings to be a useful tool in remote pressure and oxygen sensing in various fields, such as aircraft design and healthcare

Fast-response oxygen sensitive transparent coating for inner pressure ratiometric optical mapping

In this work, dual-luminophore self-referenced pressure sensitive paint (PSP) was prepared with siloxane precursors by using copolymerizable silane-functionalized carbon dots (SiCDs) as a reference probe and a newly synthesized silane-modified ruthenium complex (Ru-silane) as the sensitive probe respectively. The PSP is fully sprayable in the preparation of bi-layer thin coatings via a sol-gel process, by which a SiCD copolymerized silicone base layer was firstly constructed and subsequently covered by a Ru-silane grafted top layer. The resultant optical sensor is transparent, having a transmittance as high as 80%, besides the chemical bonding of the probes had favorably improved the stability of the luminescence properties. Based on the oxygen quenching mechanism, such transparent PSP coatings allowed efficient determination of the sudden changes of surface pressure in an inner flow channel with a time response of 1.3 ms, while the measurement can be performed from either the front side or the reverse side of the coating. Furthermore, the 2D pressure map can be quantified by calculating the intensity ratio of SiCDs to Ru-silane photoluminescence and thereby improved the accuracy of the measurement. We thus expect the transparent PSP coatings to be a useful tool in remote pressure and oxygen sensing in various fields, such as aircraft design and healthcare

Fe(TCNQ)₂ Nanorod Array: A Conductive Non-Noble-Metal Electrocatalyst toward Water Oxidation in Alkaline Media

It is extremely desired to develop cost-effective and high-efficient water oxidation electrocatalysts in alkaline electrolytes. In this Letter, we report the topotactic conversion of Cu­(tetracyanoquinodimethane) nanoarray, denoted as Cu­(TCNQ), into Fe­(TCNQ)₂ nanoarray via low-temperature cationic exchange. As a 3D electrode, such Fe­(TCNQ)₂ possesses superior oxygen evolution reaction (OER) performance needing overpotentials as low as 321 and 353 mV to afford 20 and 50 mA cm^–2 in 1.0 M KOH, respectively. Remarkably enough, such a catalyst shows good durability in the long term electrochemical process with its catalytic activity being retained for 25 h at lowest. This work demonstrates that Fe­(TCNQ)₂ nanoarray may open up new possibilities for OER application

Carbon dots and ruthenium doped oxygen sensitive nanofibrous membranes for monitoring the respiration of agricultural products

During the storage of agricultural products, the oxygen concentration in the packages represents the level of food respiration and hence indicates its freshness. Herein, self-referenced photoluminescent oxygen sensitive fibrous membranes were prepared, with the inclusion of an oxygen-sensitive probe, i.e. tris (4,7-diphenyl-1,10-phenanthroline) ruthenium (II) dichloride (RuDPP), with an oxygen-insensitive luminophore, i.e. silane-functionalized carbon dots (SiCDs). Silicone was selected as the matrix, obtained via sol-gel process, and was electrospun to get nanofibers containing mesoporous microstructure and with high oxygen permeability. The as-prepared RuDPP@SiCDs/SiO2 fibrous membranes possessed hydrophobicity and exhibited ideal oxygen sensitivity, which realized a remote evaluation of the freshness of packaged fruits, through ratiometric photoluminescence imaging on the concentration change of environmental oxygen. The results indicate that such kind of oxygen-sensitive fiber membranes are capable as an optical oxygen sensor for agricultural applications