In this work, PbS/ZnO, CdS/ZnO and CdSe/ZnO hierarchical heterostructures have been successfully synthesized by combining water bath and chemical bath deposition (CBD) methods on indium-doped tin oxide (ITO). Scanning electron microscopy (SEM) results show that quantum dots (QDs) certainly form on the pre-grown ZnO nanorod (NR) and nanotube (NT) arrays. The amount of QDs capped on ZnO could be regulated by varying the cycle times. The photocatalytic activity of the QD-sensitized ZnO is investigated by decomposition of methyl orange (MO) under irradiation, which show remarkable enhancement compared to bare ZnO. The ZnO NTs sensitized by PbS QDs have the highest catalytic activity among the three QDs (PbS, CdS and CdSe QDs). The UV-vis absorption diagrams and the Ct/C0 curves reveal that 8PbS/ZnO NTs have the highest catalytic activity, which can degrade MO (20 mg L−1) into a colorless solution within 30 min. Meanwhile, the synthetic methodology described herein provides an effective approach for fabricating a variety of photocatalysts. The heterostructured nanomaterials have significant potential to solve environmental and energy issues.

•The probe works at near-infrared light regions.•The probe functions as an “off-on” sensor for S2−.•The detection limit for S2− is 0.15 μM.Sulfide plays distinct roles in biological systems. More sensitive probes are essential for the fluorescent detection of S2−. The NIR probe IR800-DPII, which has been synthesized based on heptamethine cyanine and NBD, is able to function as an “off-on” fluorescence sensor for detecting S2− through substrate-induced cleavage mechanism.

In this work, three different CuSCN nanostructures (NSs), hexagonal prism-like (3D), pyramid-like (2D) and nanowire structures (NWs) are first applied to inverted heterojunction perovskite solar cells as p-type inorganic hole transport layers (HTLs) using a moderate electrodeposition method at room temperature. It is revealed that the crystal structure and the thickness of the CuSCN layer can dramatically regulate the morphology and the crystal orientation behavior of perovskite absorbing layers, which will further have a significant influence on the following device performance. Compared with the other two nanostructured CuSCN HTLs, devices based on 3D structured CuSCN HTLs exhibit better performance mainly attributed to the high crystalline quality of perovskite films controlled by the well-oriented hexagonal prism-like nanostructures of CuSCN. After optimization, a maximum power conversion efficiency (PCE) of 11.40% has been obtained with 3D CuSCN which has a thickness of 200 nm. It is the highest value among the current reports using nanostructured CuSCN as an inorganic HTL in inverted PSCs. The dominating effect of CuSCN nanostructures on the crystal quality of perovskites provides guidelines for future material optimization and device efficiency enhancement.

Herein, we report the performance of CsPbX3 (X = Cl, Br, and I) perovskite quantum dots (QDs) for photocatalytic degradation of organic dyes. The photocatalytic performance of CsPbX3 QDs was characterized by UV-vis absorption spectra and ESI-MS, which evaluated their ability of degrading methyl orange (MO) solution under visible light irradiation. Interestingly, both CsPbCl3 and CsPbBr3 QDs show excellent photocatalytic activities, which can decompose the MO solution into a colorless solution within 100 min. This study demonstrates the potential of CsPbX3 QDs in the degradation of organic dyes and environmentally friendly applications. Moreover, the integration of CsPbX3 QDs and photocatalysis provides a new insight for the design of new photocatalysts.

The macromolecule, PPV-NMe3+-DO3A-Gd, in which paramagnetic DO3A-Gd units were introduced into a fluorescent polymer PPV-NMe3+, was synthesized. It inherited the fluorescent properties of PPV-NMe3+ and gained the magnetic relaxivity of DO3A-Gd. PPV-NMe3+-DO3A-Gd was potential to function as a fluorescent/MRI dual-modal contrast agent.The instructions of the box below: The side chains of the fluorescent conjugated polymer PPV-NMe3+ were modified with 1, 4, 7, 10-tetraazacyclododecane-1, 4, 7-triacetic acid gadolinium chelate (DO3A-Gd) units through ‘Cu (I)-catalyzed azide-Alkyne Cycloaddition (CuAAC)’ reactions, which a kind of ‘click reaction’. The final product, PPV-NMe3+-DO3A-Gd, can achieve dual-modal Fluorescent/MR imaging.

A synthesized blue fluorescent protein (BFP) chromophore analogue 2-BFP ((4Z)-4-[(1H-imidazol-2-yl)methylene]-1-methyl-2-phenyl-1H-imidazol-5(4H)-one) displays dual fluorescent emission that arises from the same Z-isomer. The larger Stokes shift emission is a result of excited-state intramolecular proton transfer (ESIPT) mediated by an N–H···N type of hydrogen bond. Compared to other green fluorescent protein (GFP) analogues with ESIPT such as o-HBDI, 2-BFP possesses greatly enhanced quantum yields and much slower proton-transfer rates. In addition, fluorescence up-conversion experiments revealed two rising components of lifetime for the tautomer formation of 2-BFP. The results imply that the relaxation of the N* state in 2-BFP triggers the proton transfer of the molecule. The weaker photoacidity of N–H is proposed to be crucial for these photophysical and photochemical properties. Finally, the ESIPT process in 2-BFP is inhibited in protic solvents (MeOH) or by the formation of metal–chelate complexes, providing insights for further developments and applications of ESIPT molecules.Keywords: dual fluorescent emission; excited-state intramolecular proton transfer; fluorescence quantum yield; fluorescence up-conversion; green fluorescent protein; proton-transfer rate;

In this work, PbS/ZnO, CdS/ZnO and CdSe/ZnO hierarchical heterostructures have been successfully synthesized by combining water bath and chemical bath deposition (CBD) methods on indium-doped tin oxide (ITO). Scanning electron microscopy (SEM) results show that quantum dots (QDs) certainly form on the pre-grown ZnO nanorod (NR) and nanotube (NT) arrays. The amount of QDs capped on ZnO could be regulated by varying the cycle times. The photocatalytic activity of the QD-sensitized ZnO is investigated by decomposition of methyl orange (MO) under irradiation, which show remarkable enhancement compared to bare ZnO. The ZnO NTs sensitized by PbS QDs have the highest catalytic activity among the three QDs (PbS, CdS and CdSe QDs). The UV-vis absorption diagrams and the Ct/C0 curves reveal that 8PbS/ZnO NTs have the highest catalytic activity, which can degrade MO (20 mg L−1) into a colorless solution within 30 min. Meanwhile, the synthetic methodology described herein provides an effective approach for fabricating a variety of photocatalysts. The heterostructured nanomaterials have significant potential to solve environmental and energy issues.